feat: NCS-14 implemented insufficient moves rule (#30)

Reviewed-on: #30
Co-authored-by: Janis <janis.e.20@gmx.de>
Co-committed-by: Janis <janis.e.20@gmx.de>

.claude/memory/MEMORY.md

@@ -1,9 +0,0 @@
-# Memory Index
-
-## Feedback
-- [feedback_keep_structure_updated.md](feedback_keep_structure_updated.md) — Update structure memory files whenever source files are added, removed, or changed
-
-## Project Structure
-- [project_structure_root.md](project_structure_root.md) — Top-level layout, modules list, VERSIONS map, navigation rules (skip `build/`, `.gradle/`, `.idea/`)
-- [project_structure_api.md](project_structure_api.md) — `modules/api`: all files and types (Board, Piece, Square, GameState, Move, ApiResponse, PlayerInfo)
-- [project_structure_core.md](project_structure_core.md) — `modules/core`: all files and types (GameContext, GameRules, MoveValidator, GameController, Parser, Renderer)

.claude/memory/feedback_keep_structure_updated.md

@@ -1,16 +0,0 @@
----
-name: keep-structure-memory-updated
-description: Always update the project structure memory files when adding, removing, or changing source files
-type: feedback
----
-
-After any change that adds, removes, renames, or significantly alters a source file, update the relevant structure memory file:
-
-- New/renamed/deleted file in `modules/api` → update `project_structure_api.md`
-- New/renamed/deleted file in `modules/core` → update `project_structure_core.md`
-- New module, dependency version change, or new top-level directory → update `project_structure_root.md`
-- New module added → create a new `project_structure_<module>.md` and add it to `MEMORY.md`
-
-**Why:** Structure memories are the primary navigation aid. Stale entries cause wasted exploration.
-
-**How to apply:** Treat the structure memory update as part of completing any implementation task — do it in the same session, not as a follow-up.

.claude/memory/project_structure_api.md

@@ -1,51 +0,0 @@
----
-name: module-api-structure
-description: File and type overview for the modules/api module (shared domain types)
-type: project
----
-
-# Module: `modules/api`
-
-**Purpose:** Shared domain model — pure data types with no game logic. Depended on by `modules/core`.
-
-**Gradle:** `id("scala")`, no `application` plugin. No Quarkus. Uses scoverage plugin.
-
-**Package root:** `de.nowchess.api`
-
-## Source files (`src/main/scala/de/nowchess/api/`)
-
-### `board/`
-| File | Contents |
-|------|----------|
-| `Board.scala` | `opaque type Board = Map[Square, Piece]` — extensions: `pieceAt`, `withMove`, `pieces`; `Board.initial` sets up start position |
-| `Color.scala` | `enum Color { White, Black }` — `.opposite`, `.label` |
-| `Piece.scala` | `case class Piece(color, pieceType)` — convenience vals `WhitePawn`…`BlackKing` |
-| `PieceType.scala` | `enum PieceType { Pawn, Knight, Bishop, Rook, Queen, King }` — `.label` |
-| `Square.scala` | `enum File { A–H }`, `enum Rank { R1–R8 }`, `case class Square(file, rank)` — `.toString` algebraic, `Square.fromAlgebraic(s)` |
-
-### `game/`
-| File | Contents |
-|------|----------|
-| `GameState.scala` | `case class CastlingRights(kingSide, queenSide)` + `.None`/`.Both`; `enum GameResult { WhiteWins, BlackWins, Draw }`; `enum GameStatus { NotStarted, InProgress, Finished(result) }`; `case class GameState(piecePlacement, activeColor, castlingWhite, castlingBlack, enPassantTarget, halfMoveClock, fullMoveNumber, status)` — FEN-compatible snapshot |
-
-### `move/`
-| File | Contents |
-|------|----------|
-| `Move.scala` | `enum PromotionPiece { Knight, Bishop, Rook, Queen }`; `enum MoveType { Normal, CastleKingside, CastleQueenside, EnPassant, Promotion(piece) }`; `case class Move(from, to, moveType = Normal)` |
-
-### `player/`
-| File | Contents |
-|------|----------|
-| `PlayerInfo.scala` | `opaque type PlayerId = String`; `case class PlayerInfo(id: PlayerId, displayName: String)` |
-
-### `response/`
-| File | Contents |
-|------|----------|
-| `ApiResponse.scala` | `sealed trait ApiResponse[+A]` → `Success[A](data)` / `Failure(errors)`; `case class ApiError(code, message, field?)`; `case class Pagination(page, pageSize, totalItems)` + `.totalPages`; `case class PagedResponse[A](items, pagination)` |
-
-## Test files (`src/test/scala/de/nowchess/api/`)
-Mirror of main structure — one `*Test.scala` per source file using `AnyFunSuite with Matchers`.
-
-## Notes
-- `GameState` is FEN-style but `Board` (in `core`) is a `Map[Square,Piece]` — the two are separate representations
-- `CastlingRights` is defined here in `api`; the castling logic lives in `core`

.claude/memory/project_structure_core.md

@@ -1,48 +0,0 @@
----
-name: module-core-structure
-description: File and type overview for the modules/core module (TUI chess engine)
-type: project
----
-
-# Module: `modules/core`
-
-**Purpose:** Standalone TUI chess application. All game logic, move validation, rendering. Depends on `modules/api`.
-
-**Gradle:** `id("scala")` + `application` plugin. Main class: `de.nowchess.chess.Main`. Uses scoverage plugin.
-
-**Package root:** `de.nowchess.chess`
-
-## Source files (`src/main/scala/de/nowchess/chess/`)
-
-### Root
-| File | Contents |
-|------|----------|
-| `Main.scala` | Entry point — prints welcome, starts `GameController.gameLoop(GameContext.initial, Color.White)` |
-
-### `controller/`
-| File | Contents |
-|------|----------|
-| `GameController.scala` | `sealed trait MoveResult` ADT: `Quit`, `InvalidFormat`, `NoPiece`, `WrongColor`, `IllegalMove`, `Moved`, `MovedInCheck`, `Checkmate`, `Stalemate`; `object GameController` — `processMove(ctx, turn, raw): MoveResult` (pure), `gameLoop(ctx, turn)` (I/O loop), `applyRightsRevocation(...)` (castling rights bookkeeping) |
-| `Parser.scala` | `object Parser` — `parseMove(input): Option[(Square, Square)]` parses coordinate notation e.g. `"e2e4"` |
-
-### `logic/`
-| File | Contents |
-|------|----------|
-| `GameContext.scala` | `enum CastleSide { Kingside, Queenside }`; `case class GameContext(board, whiteCastling, blackCastling)` — `.castlingFor(color)`, `.withUpdatedRights(color, rights)`; `GameContext.initial`; `extension (Board).withCastle(color, side)` moves king+rook atomically |
-| `GameRules.scala` | `enum PositionStatus { Normal, InCheck, Mated, Drawn }`; `object GameRules` — `isInCheck(board, color)`, `legalMoves(ctx, color): Set[(Square,Square)]`, `gameStatus(ctx, color): PositionStatus` |
-| `MoveValidator.scala` | `object MoveValidator` — `isLegal(board, from, to)`, `legalTargets(board, from): Set[Square]` (board-only, no castling), `legalTargets(ctx, from)` (context-aware, includes castling), `isCastle`, `castleSide`, `castlingTargets(ctx, color)` — full castling legality (empty squares, no check through transit) |
-
-### `view/`
-| File | Contents |
-|------|----------|
-| `Renderer.scala` | `object Renderer` — `render(board): String` outputs ANSI-colored board with file/rank labels |
-| `PieceUnicode.scala` | `extension (Piece).unicode: String` maps each piece to its Unicode chess symbol |
-
-## Test files (`src/test/scala/de/nowchess/chess/`)
-Mirror of main structure — one `*Test.scala` per source file using `AnyFunSuite with Matchers`.
-
-## Key design notes
-- `MoveValidator` has two overloaded `legalTargets`: one takes `Board` (geometry only), one takes `GameContext` (adds castling)
-- `GameRules.legalMoves` filters by check — it calls `MoveValidator.legalTargets(ctx, from)` then simulates each move
-- Castling rights revocation is in `GameController.applyRightsRevocation`, triggered after every move
-- No `@QuarkusTest` — this module is a plain Scala application, not a Quarkus service

.claude/memory/project_structure_root.md

@@ -1,55 +0,0 @@
----
-name: project-root-structure
-description: Top-level project structure, modules list, and navigation notes for NowChessSystems
-type: project
----
-
-# NowChessSystems — Root Structure
-
-## Directory layout (skip `build/`, `.gradle/`, `.idea/`)
-
-```
-NowChessSystems/
-├── build.gradle.kts          # Root: sonarqube plugin, VERSIONS map
-├── settings.gradle.kts       # include(":modules:core", ":modules:api")
-├── gradlew / gradlew.bat
-├── CLAUDE.md                 # Project instructions for Claude Code
-├── .claude/
-│   ├── CLAUDE.MD             # Working agreement (plan/verify/unresolved)
-│   ├── settings.json
-│   └── agents/               # architect, code-reviewer, gradle-builder, scala-implementer, test-writer
-├── docs/
-│   ├── Claude-Skills.md
-│   ├── Security.md
-│   └── unresolved.md
-├── jacoco-reporter/          # Python scripts for coverage gap reporting
-└── modules/
-    ├── api/                  # Shared domain types (no logic)
-    └── core/                 # TUI chess engine + game logic
-```
-
-## Modules
-
-| Module | Gradle path | Purpose |
-|--------|-------------|---------|
-| `api` | `:modules:api` | Shared domain model: Board, Piece, Move, GameState, ApiResponse |
-| `core` | `:modules:core` | TUI chess app: game logic, move validation, rendering |
-
-`core` depends on `api` via `implementation(project(":modules:api"))`.
-
-## VERSIONS (root `build.gradle.kts`)
-
-| Key | Value |
-|-----|-------|
-| `QUARKUS_SCALA3` | 1.0.0 |
-| `SCALA3` | 3.5.1 |
-| `SCALA_LIBRARY` | 2.13.18 |
-| `SCALATEST` | 3.2.19 |
-| `SCALATEST_JUNIT` | 0.1.11 |
-| `SCOVERAGE` | 2.1.1 |
-
-## Navigation rules
-- **Always skip** `build/`, `.gradle/`, `.idea/` when exploring — they are generated artifacts
-- Tests use `AnyFunSuite with Matchers` (ScalaTest), not JUnit `@Test`
-- No Quarkus in current modules — Quarkus is planned for future services
-- Agent workflow: architect → scala-implementer → test-writer → gradle-builder → code-reviewer

.claude/settings.json

@@ -1,6 +1,6 @@
 {
   "enabledPlugins": {
-    "superpowers@claude-plugins-official": true,
-    "ui-ux-pro-max@ui-ux-pro-max-skill": true
+    "superpowers@claude-plugins-official": false,
+    "ui-ux-pro-max@ui-ux-pro-max-skill": false
   }
 }

.codesight/CODESIGHT.md

@@ -0,0 +1,203 @@
+# NowChessSystems — AI Context Map
+
+> **Stack:** raw-http | none | unknown | scala
+
+> 0 routes | 0 models | 0 components | 35 lib files | 0 env vars | 0 middleware
+> **Token savings:** this file is ~3.700 tokens. Without it, AI exploration would cost ~18.200 tokens. **Saves ~14.500 tokens per conversation.**
+
+---
+
+# Libraries
+
+- `jacoco-reporter/scoverage_coverage_gaps.py`
+  - function parse_scoverage_xml: (xml_path) -> tuple[dict, list[ClassGap]]
+  - function format_agent: (project_stats, classes) -> str
+  - function format_json: (project_stats, classes) -> str
+  - function format_markdown: (project_stats, classes) -> str
+  - function format_module_gaps: (module_name, classes, stmt_pct) -> str
+  - function run_scan_modules: (modules_dir, package_filter, min_coverage) -> None
+  - _...4 more_
+- `jacoco-reporter/test_gaps.py`
+  - function parse_suite_xml: (xml_path) -> SuiteResult
+  - function load_module: (module_dir, results_subdir) -> Optional[ModuleResult]
+  - function format_module: (mod) -> str
+  - function run: (modules_dir, results_subdir, module_filter) -> None
+  - function main: () -> None
+  - class TestCase
+  - _...2 more_
+- `modules/api/src/main/scala/de/nowchess/api/board/Board.scala`
+  - class Board
+  - function apply
+  - function pieceAt
+  - function updated
+  - function removed
+  - function withMove
+  - _...2 more_
+- `modules/api/src/main/scala/de/nowchess/api/board/CastlingRights.scala`
+  - function hasAnyRights
+  - function hasRights
+  - function revokeColor
+  - function revokeKingSide
+  - function revokeQueenSide
+  - class CastlingRights
+- `modules/api/src/main/scala/de/nowchess/api/board/Color.scala` — function opposite, function label
+- `modules/api/src/main/scala/de/nowchess/api/board/Piece.scala` — class Piece
+- `modules/api/src/main/scala/de/nowchess/api/board/PieceType.scala` — function label
+- `modules/api/src/main/scala/de/nowchess/api/board/Square.scala`
+  - class Square
+  - function fromAlgebraic
+  - function offset
+- `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala`
+  - function withBoard
+  - function withTurn
+  - function withCastlingRights
+  - function withEnPassantSquare
+  - function withHalfMoveClock
+  - function withMove
+  - _...2 more_
+- `modules/api/src/main/scala/de/nowchess/api/player/PlayerInfo.scala` — class PlayerId, function apply
+- `modules/api/src/main/scala/de/nowchess/api/response/ApiResponse.scala`
+  - class ApiResponse
+  - function error
+  - function totalPages
+- `modules/core/src/main/scala/de/nowchess/chess/command/Command.scala`
+  - class Command
+  - function execute
+  - function undo
+  - function description
+  - class MoveResult
+- `modules/core/src/main/scala/de/nowchess/chess/command/CommandInvoker.scala`
+  - class CommandInvoker
+  - function execute
+  - function undo
+  - function redo
+  - function history
+  - function getCurrentIndex
+  - _...3 more_
+- `modules/core/src/main/scala/de/nowchess/chess/controller/Parser.scala` — class Parser, function parseMove
+- `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`
+  - class GameEngine
+  - function isPendingPromotion
+  - function board
+  - function turn
+  - function context
+  - function canUndo
+  - _...10 more_
+- `modules/core/src/main/scala/de/nowchess/chess/observer/Observer.scala`
+  - function context
+  - class Observer
+  - function onGameEvent
+  - class Observable
+  - function subscribe
+  - function unsubscribe
+  - _...1 more_
+- `modules/io/src/main/scala/de/nowchess/io/GameContextExport.scala` — class GameContextExport, function exportGameContext
+- `modules/io/src/main/scala/de/nowchess/io/GameContextImport.scala` — class GameContextImport, function importGameContext
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenExporter.scala`
+  - class FenExporter
+  - function boardToFen
+  - function gameContextToFen
+  - function exportGameContext
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParser.scala`
+  - class FenParser
+  - function parseFen
+  - function importGameContext
+  - function parseBoard
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParserCombinators.scala`
+  - class FenParserCombinators
+  - function parseFen
+  - function parseBoard
+  - function importGameContext
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParserFastParse.scala`
+  - class FenParserFastParse
+  - function parseFen
+  - function parseBoard
+  - function importGameContext
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParserSupport.scala` — function buildSquares
+- `modules/io/src/main/scala/de/nowchess/io/pgn/PgnExporter.scala`
+  - class PgnExporter
+  - function exportGameContext
+  - function exportGame
+- `modules/io/src/main/scala/de/nowchess/io/pgn/PgnParser.scala`
+  - class PgnParser
+  - function validatePgn
+  - function importGameContext
+  - function parsePgn
+  - function parseAlgebraicMove
+- `modules/rule/src/main/scala/de/nowchess/rules/RuleSet.scala`
+  - class RuleSet
+  - function candidateMoves
+  - function legalMoves
+  - function allLegalMoves
+  - function isCheck
+  - function isCheckmate
+  - _...4 more_
+- `modules/rule/src/main/scala/de/nowchess/rules/sets/DefaultRules.scala`
+  - class DefaultRules
+  - function loop
+  - function toMoves
+  - function loop
+- `modules/ui/src/main/scala/de/nowchess/ui/Main.scala` — class Main, function main
+- `modules/ui/src/main/scala/de/nowchess/ui/gui/ChessBoardView.scala`
+  - class ChessBoardView
+  - function updateBoard
+  - function updateUndoRedoButtons
+  - function showMessage
+  - function showPromotionDialog
+- `modules/ui/src/main/scala/de/nowchess/ui/gui/ChessGUI.scala`
+  - class ChessGUIApp
+  - class ChessGUILauncher
+  - function getEngine
+  - function launch
+- `modules/ui/src/main/scala/de/nowchess/ui/gui/GUIObserver.scala` — class GUIObserver
+- `modules/ui/src/main/scala/de/nowchess/ui/gui/PieceSprites.scala`
+  - class PieceSprites
+  - function loadPieceImage
+  - class SquareColors
+- `modules/ui/src/main/scala/de/nowchess/ui/terminal/TerminalUI.scala` — class TerminalUI, function start
+- `modules/ui/src/main/scala/de/nowchess/ui/utils/PieceUnicode.scala` — function unicode
+- `modules/ui/src/main/scala/de/nowchess/ui/utils/Renderer.scala` — class Renderer, function render
+
+---
+
+# Dependency Graph
+
+## Most Imported Files (change these carefully)
+
+- `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala` — imported by **28** files
+- `modules/api/src/main/scala/de/nowchess/api/board/Square.scala` — imported by **21** files
+- `modules/api/src/main/scala/de/nowchess/api/board/Color.scala` — imported by **19** files
+- `modules/api/src/main/scala/de/nowchess/api/move/Move.scala` — imported by **14** files
+- `modules/api/src/main/scala/de/nowchess/api/board/Board.scala` — imported by **13** files
+- `modules/api/src/main/scala/de/nowchess/api/board/Piece.scala` — imported by **10** files
+- `modules/api/src/main/scala/de/nowchess/api/board/PieceType.scala` — imported by **9** files
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParser.scala` — imported by **9** files
+- `modules/rule/src/main/scala/de/nowchess/rules/sets/DefaultRules.scala` — imported by **8** files
+- `modules/io/src/main/scala/de/nowchess/io/GameContextImport.scala` — imported by **7** files
+- `modules/api/src/main/scala/de/nowchess/api/board/CastlingRights.scala` — imported by **4** files
+- `modules/io/src/main/scala/de/nowchess/io/GameContextExport.scala` — imported by **4** files
+- `modules/rule/src/main/scala/de/nowchess/rules/RuleSet.scala` — imported by **4** files
+- `modules/core/src/main/scala/de/nowchess/chess/observer/Observer.scala` — imported by **4** files
+- `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala` — imported by **4** files
+- `modules/io/src/main/scala/de/nowchess/io/pgn/PgnParser.scala` — imported by **2** files
+- `modules/io/src/main/scala/de/nowchess/io/pgn/PgnExporter.scala` — imported by **2** files
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenExporter.scala` — imported by **2** files
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParserSupport.scala` — imported by **2** files
+- `modules/core/src/main/scala/de/nowchess/chess/controller/Parser.scala` — imported by **1** files
+
+## Import Map (who imports what)
+
+- `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala` ← `modules/core/src/main/scala/de/nowchess/chess/command/Command.scala`, `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/main/scala/de/nowchess/chess/observer/Observer.scala`, `modules/core/src/test/scala/de/nowchess/chess/command/CommandInvokerBranchTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/command/CommandInvokerTest.scala` +23 more
+- `modules/api/src/main/scala/de/nowchess/api/board/Square.scala` ← `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala`, `modules/api/src/main/scala/de/nowchess/api/move/Move.scala`, `modules/api/src/test/scala/de/nowchess/api/game/GameContextTest.scala`, `modules/api/src/test/scala/de/nowchess/api/move/MoveTest.scala`, `modules/core/src/main/scala/de/nowchess/chess/command/Command.scala` +16 more
+- `modules/api/src/main/scala/de/nowchess/api/board/Color.scala` ← `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala`, `modules/api/src/test/scala/de/nowchess/api/game/GameContextTest.scala`, `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/main/scala/de/nowchess/chess/observer/Observer.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/EngineTestHelpers.scala` +14 more
+- `modules/api/src/main/scala/de/nowchess/api/move/Move.scala` ← `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala`, `modules/api/src/test/scala/de/nowchess/api/board/BoardTest.scala`, `modules/api/src/test/scala/de/nowchess/api/game/GameContextTest.scala`, `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineIntegrationTest.scala` +9 more
+- `modules/api/src/main/scala/de/nowchess/api/board/Board.scala` ← `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala`, `modules/api/src/test/scala/de/nowchess/api/game/GameContextTest.scala`, `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/EngineTestHelpers.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineGameEndingTest.scala` +8 more
+- `modules/api/src/main/scala/de/nowchess/api/board/Piece.scala` ← `modules/core/src/main/scala/de/nowchess/chess/command/Command.scala`, `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEnginePromotionTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineScenarioTest.scala`, `modules/rule/src/test/scala/de/nowchess/rule/DefaultRulesStateTransitionsTest.scala` +5 more
+- `modules/api/src/main/scala/de/nowchess/api/board/PieceType.scala` ← `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineIntegrationTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEnginePromotionTest.scala`, `modules/rule/src/test/scala/de/nowchess/rule/DefaultRulesStateTransitionsTest.scala`, `modules/rule/src/test/scala/de/nowchess/rule/DefaultRulesTest.scala` +4 more
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParser.scala` ← `modules/core/src/test/scala/de/nowchess/chess/engine/EngineTestHelpers.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineLoadGameTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineNotationTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEnginePromotionTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineScenarioTest.scala` +4 more
+- `modules/rule/src/main/scala/de/nowchess/rules/sets/DefaultRules.scala` ← `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/EngineTestHelpers.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineIntegrationTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEnginePromotionTest.scala`, `modules/io/src/main/scala/de/nowchess/io/pgn/PgnExporter.scala` +3 more
+- `modules/io/src/main/scala/de/nowchess/io/GameContextImport.scala` ← `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineIntegrationTest.scala`, `modules/io/src/main/scala/de/nowchess/io/fen/FenParser.scala`, `modules/io/src/main/scala/de/nowchess/io/fen/FenParserCombinators.scala`, `modules/io/src/main/scala/de/nowchess/io/fen/FenParserFastParse.scala` +2 more
+
+---
+
+_Generated by [codesight](https://github.com/Houseofmvps/codesight) — see your codebase clearly_

.codesight/graph.md

@@ -0,0 +1,37 @@
+# Dependency Graph
+
+## Most Imported Files (change these carefully)
+
+- `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala` — imported by **28** files
+- `modules/api/src/main/scala/de/nowchess/api/board/Square.scala` — imported by **21** files
+- `modules/api/src/main/scala/de/nowchess/api/board/Color.scala` — imported by **19** files
+- `modules/api/src/main/scala/de/nowchess/api/move/Move.scala` — imported by **14** files
+- `modules/api/src/main/scala/de/nowchess/api/board/Board.scala` — imported by **13** files
+- `modules/api/src/main/scala/de/nowchess/api/board/Piece.scala` — imported by **10** files
+- `modules/api/src/main/scala/de/nowchess/api/board/PieceType.scala` — imported by **9** files
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParser.scala` — imported by **9** files
+- `modules/rule/src/main/scala/de/nowchess/rules/sets/DefaultRules.scala` — imported by **8** files
+- `modules/io/src/main/scala/de/nowchess/io/GameContextImport.scala` — imported by **7** files
+- `modules/api/src/main/scala/de/nowchess/api/board/CastlingRights.scala` — imported by **4** files
+- `modules/io/src/main/scala/de/nowchess/io/GameContextExport.scala` — imported by **4** files
+- `modules/rule/src/main/scala/de/nowchess/rules/RuleSet.scala` — imported by **4** files
+- `modules/core/src/main/scala/de/nowchess/chess/observer/Observer.scala` — imported by **4** files
+- `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala` — imported by **4** files
+- `modules/io/src/main/scala/de/nowchess/io/pgn/PgnParser.scala` — imported by **2** files
+- `modules/io/src/main/scala/de/nowchess/io/pgn/PgnExporter.scala` — imported by **2** files
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenExporter.scala` — imported by **2** files
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParserSupport.scala` — imported by **2** files
+- `modules/core/src/main/scala/de/nowchess/chess/controller/Parser.scala` — imported by **1** files
+
+## Import Map (who imports what)
+
+- `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala` ← `modules/core/src/main/scala/de/nowchess/chess/command/Command.scala`, `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/main/scala/de/nowchess/chess/observer/Observer.scala`, `modules/core/src/test/scala/de/nowchess/chess/command/CommandInvokerBranchTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/command/CommandInvokerTest.scala` +23 more
+- `modules/api/src/main/scala/de/nowchess/api/board/Square.scala` ← `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala`, `modules/api/src/main/scala/de/nowchess/api/move/Move.scala`, `modules/api/src/test/scala/de/nowchess/api/game/GameContextTest.scala`, `modules/api/src/test/scala/de/nowchess/api/move/MoveTest.scala`, `modules/core/src/main/scala/de/nowchess/chess/command/Command.scala` +16 more
+- `modules/api/src/main/scala/de/nowchess/api/board/Color.scala` ← `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala`, `modules/api/src/test/scala/de/nowchess/api/game/GameContextTest.scala`, `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/main/scala/de/nowchess/chess/observer/Observer.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/EngineTestHelpers.scala` +14 more
+- `modules/api/src/main/scala/de/nowchess/api/move/Move.scala` ← `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala`, `modules/api/src/test/scala/de/nowchess/api/board/BoardTest.scala`, `modules/api/src/test/scala/de/nowchess/api/game/GameContextTest.scala`, `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineIntegrationTest.scala` +9 more
+- `modules/api/src/main/scala/de/nowchess/api/board/Board.scala` ← `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala`, `modules/api/src/test/scala/de/nowchess/api/game/GameContextTest.scala`, `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/EngineTestHelpers.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineGameEndingTest.scala` +8 more
+- `modules/api/src/main/scala/de/nowchess/api/board/Piece.scala` ← `modules/core/src/main/scala/de/nowchess/chess/command/Command.scala`, `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEnginePromotionTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineScenarioTest.scala`, `modules/rule/src/test/scala/de/nowchess/rule/DefaultRulesStateTransitionsTest.scala` +5 more
+- `modules/api/src/main/scala/de/nowchess/api/board/PieceType.scala` ← `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineIntegrationTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEnginePromotionTest.scala`, `modules/rule/src/test/scala/de/nowchess/rule/DefaultRulesStateTransitionsTest.scala`, `modules/rule/src/test/scala/de/nowchess/rule/DefaultRulesTest.scala` +4 more
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParser.scala` ← `modules/core/src/test/scala/de/nowchess/chess/engine/EngineTestHelpers.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineLoadGameTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineNotationTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEnginePromotionTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineScenarioTest.scala` +4 more
+- `modules/rule/src/main/scala/de/nowchess/rules/sets/DefaultRules.scala` ← `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/EngineTestHelpers.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineIntegrationTest.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEnginePromotionTest.scala`, `modules/io/src/main/scala/de/nowchess/io/pgn/PgnExporter.scala` +3 more
+- `modules/io/src/main/scala/de/nowchess/io/GameContextImport.scala` ← `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`, `modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineIntegrationTest.scala`, `modules/io/src/main/scala/de/nowchess/io/fen/FenParser.scala`, `modules/io/src/main/scala/de/nowchess/io/fen/FenParserCombinators.scala`, `modules/io/src/main/scala/de/nowchess/io/fen/FenParserFastParse.scala` +2 more

.codesight/libs.md

@@ -0,0 +1,150 @@
+# Libraries
+
+- `jacoco-reporter/scoverage_coverage_gaps.py`
+  - function parse_scoverage_xml: (xml_path) -> tuple[dict, list[ClassGap]]
+  - function format_agent: (project_stats, classes) -> str
+  - function format_json: (project_stats, classes) -> str
+  - function format_markdown: (project_stats, classes) -> str
+  - function format_module_gaps: (module_name, classes, stmt_pct) -> str
+  - function run_scan_modules: (modules_dir, package_filter, min_coverage) -> None
+  - _...4 more_
+- `jacoco-reporter/test_gaps.py`
+  - function parse_suite_xml: (xml_path) -> SuiteResult
+  - function load_module: (module_dir, results_subdir) -> Optional[ModuleResult]
+  - function format_module: (mod) -> str
+  - function run: (modules_dir, results_subdir, module_filter) -> None
+  - function main: () -> None
+  - class TestCase
+  - _...2 more_
+- `modules/api/src/main/scala/de/nowchess/api/board/Board.scala`
+  - class Board
+  - function apply
+  - function pieceAt
+  - function updated
+  - function removed
+  - function withMove
+  - _...2 more_
+- `modules/api/src/main/scala/de/nowchess/api/board/CastlingRights.scala`
+  - function hasAnyRights
+  - function hasRights
+  - function revokeColor
+  - function revokeKingSide
+  - function revokeQueenSide
+  - class CastlingRights
+- `modules/api/src/main/scala/de/nowchess/api/board/Color.scala` — function opposite, function label
+- `modules/api/src/main/scala/de/nowchess/api/board/Piece.scala` — class Piece
+- `modules/api/src/main/scala/de/nowchess/api/board/PieceType.scala` — function label
+- `modules/api/src/main/scala/de/nowchess/api/board/Square.scala`
+  - class Square
+  - function fromAlgebraic
+  - function offset
+- `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala`
+  - function withBoard
+  - function withTurn
+  - function withCastlingRights
+  - function withEnPassantSquare
+  - function withHalfMoveClock
+  - function withMove
+  - _...2 more_
+- `modules/api/src/main/scala/de/nowchess/api/player/PlayerInfo.scala` — class PlayerId, function apply
+- `modules/api/src/main/scala/de/nowchess/api/response/ApiResponse.scala`
+  - class ApiResponse
+  - function error
+  - function totalPages
+- `modules/core/src/main/scala/de/nowchess/chess/command/Command.scala`
+  - class Command
+  - function execute
+  - function undo
+  - function description
+  - class MoveResult
+- `modules/core/src/main/scala/de/nowchess/chess/command/CommandInvoker.scala`
+  - class CommandInvoker
+  - function execute
+  - function undo
+  - function redo
+  - function history
+  - function getCurrentIndex
+  - _...3 more_
+- `modules/core/src/main/scala/de/nowchess/chess/controller/Parser.scala` — class Parser, function parseMove
+- `modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala`
+  - class GameEngine
+  - function isPendingPromotion
+  - function board
+  - function turn
+  - function context
+  - function canUndo
+  - _...10 more_
+- `modules/core/src/main/scala/de/nowchess/chess/observer/Observer.scala`
+  - function context
+  - class Observer
+  - function onGameEvent
+  - class Observable
+  - function subscribe
+  - function unsubscribe
+  - _...1 more_
+- `modules/io/src/main/scala/de/nowchess/io/GameContextExport.scala` — class GameContextExport, function exportGameContext
+- `modules/io/src/main/scala/de/nowchess/io/GameContextImport.scala` — class GameContextImport, function importGameContext
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenExporter.scala`
+  - class FenExporter
+  - function boardToFen
+  - function gameContextToFen
+  - function exportGameContext
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParser.scala`
+  - class FenParser
+  - function parseFen
+  - function importGameContext
+  - function parseBoard
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParserCombinators.scala`
+  - class FenParserCombinators
+  - function parseFen
+  - function parseBoard
+  - function importGameContext
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParserFastParse.scala`
+  - class FenParserFastParse
+  - function parseFen
+  - function parseBoard
+  - function importGameContext
+- `modules/io/src/main/scala/de/nowchess/io/fen/FenParserSupport.scala` — function buildSquares
+- `modules/io/src/main/scala/de/nowchess/io/pgn/PgnExporter.scala`
+  - class PgnExporter
+  - function exportGameContext
+  - function exportGame
+- `modules/io/src/main/scala/de/nowchess/io/pgn/PgnParser.scala`
+  - class PgnParser
+  - function validatePgn
+  - function importGameContext
+  - function parsePgn
+  - function parseAlgebraicMove
+- `modules/rule/src/main/scala/de/nowchess/rules/RuleSet.scala`
+  - class RuleSet
+  - function candidateMoves
+  - function legalMoves
+  - function allLegalMoves
+  - function isCheck
+  - function isCheckmate
+  - _...4 more_
+- `modules/rule/src/main/scala/de/nowchess/rules/sets/DefaultRules.scala`
+  - class DefaultRules
+  - function loop
+  - function toMoves
+  - function loop
+- `modules/ui/src/main/scala/de/nowchess/ui/Main.scala` — class Main, function main
+- `modules/ui/src/main/scala/de/nowchess/ui/gui/ChessBoardView.scala`
+  - class ChessBoardView
+  - function updateBoard
+  - function updateUndoRedoButtons
+  - function showMessage
+  - function showPromotionDialog
+- `modules/ui/src/main/scala/de/nowchess/ui/gui/ChessGUI.scala`
+  - class ChessGUIApp
+  - class ChessGUILauncher
+  - function getEngine
+  - function launch
+- `modules/ui/src/main/scala/de/nowchess/ui/gui/GUIObserver.scala` — class GUIObserver
+- `modules/ui/src/main/scala/de/nowchess/ui/gui/PieceSprites.scala`
+  - class PieceSprites
+  - function loadPieceImage
+  - class SquareColors
+- `modules/ui/src/main/scala/de/nowchess/ui/terminal/TerminalUI.scala` — class TerminalUI, function start
+- `modules/ui/src/main/scala/de/nowchess/ui/utils/PieceUnicode.scala` — function unicode
+- `modules/ui/src/main/scala/de/nowchess/ui/utils/Renderer.scala` — class Renderer, function render

.codesight/wiki/index.md

@@ -0,0 +1,44 @@
+# NowChessSystems — Wiki
+
+_Generated 2026-04-12 — re-run `npx codesight --wiki` if the codebase has changed._
+
+Structural map compiled from source code via AST. No LLM — deterministic, 200ms.
+
+> **How to use safely:** These articles tell you WHERE things live and WHAT exists. They do not show full implementation logic. Always read the actual source files before implementing new features or making changes. Never infer how a function works from the wiki alone.
+
+## Articles
+
+- [Overview](./overview.md)
+
+## Quick Stats
+
+- Routes: **0**
+- Models: **0**
+- Components: **0**
+- Env vars: **0** required, **0** with defaults
+
+## How to Use
+
+- **New session:** read `index.md` (this file) for orientation — WHERE things are
+- **Architecture question:** read `overview.md` (~500 tokens)
+- **Domain question:** read the relevant article, then **read those source files**
+- **Database question:** read `database.md`, then read the actual schema files
+- **Before implementing anything:** read the source files listed in the article
+- **Full source context:** read `.codesight/CODESIGHT.md`
+
+## What the Wiki Does Not Cover
+
+These exist in your codebase but are **not** reflected in wiki articles:
+- Routes registered dynamically at runtime (loops, plugin factories, `app.use(dynamicRouter)`)
+- Internal routes from npm packages (e.g. Better Auth's built-in `/api/auth/*` endpoints)
+- WebSocket and SSE handlers
+- Raw SQL tables not declared through an ORM
+- Computed or virtual fields absent from schema declarations
+- TypeScript types that are not actual database columns
+- Routes marked `[inferred]` were detected via regex and may have lower precision
+- gRPC, tRPC, and GraphQL resolvers may be partially captured
+
+When in doubt, search the source. The wiki is a starting point, not a complete inventory.
+
+---
+_Last compiled: 2026-04-12 · 2 articles · [codesight](https://github.com/Houseofmvps/codesight)_

.codesight/wiki/log.md

@@ -0,0 +1,5 @@
+# Wiki Log
+
+History of `npx codesight --wiki` runs. Capped at 20 entries.
+
+## [2026-04-12 14:34:19] scan | 0 routes, 0 models, 0 components → 2 articles

.codesight/wiki/overview.md

@@ -0,0 +1,19 @@
+# NowChessSystems — Overview
+
+> **Navigation aid.** This article shows WHERE things live (routes, models, files). Read actual source files before implementing new features or making changes.
+
+**NowChessSystems** is a scala project built with raw-http.
+
+## High-Impact Files
+
+Changes to these files have the widest blast radius across the codebase:
+
+- `modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala` — imported by **28** files
+- `modules/api/src/main/scala/de/nowchess/api/board/Square.scala` — imported by **21** files
+- `modules/api/src/main/scala/de/nowchess/api/board/Color.scala` — imported by **19** files
+- `modules/api/src/main/scala/de/nowchess/api/move/Move.scala` — imported by **14** files
+- `modules/api/src/main/scala/de/nowchess/api/board/Board.scala` — imported by **13** files
+- `modules/api/src/main/scala/de/nowchess/api/board/Piece.scala` — imported by **10** files
+
+---
+_Back to [index.md](./index.md) · Generated 2026-04-12_

.gitattributes

@@ -0,0 +1,41 @@
+# Normalize text files in the repo
+* text=auto eol=lf
+
+# Keep Windows command scripts in CRLF
+*.bat text eol=crlf
+*.cmd text eol=crlf
+
+# Keep Unix shell scripts in LF
+*.sh text eol=lf
+
+# Binary assets (no EOL normalization / textual diff)
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.webp binary
+*.bmp binary
+*.ico binary
+
+# ML / model / numeric artifacts
+*.bin binary
+*.pt binary
+*.pth binary
+*.onnx binary
+*.h5 binary
+*.hdf5 binary
+*.pb binary
+*.tflite binary
+*.npy binary
+*.npz binary
+*.safetensors binary
+
+# Firmware / hex-like artifacts
+*.hex binary
+
+# Packaged binaries
+*.jar binary
+*.zip binary
+*.7z binary
+*.gz binary
+

.gitignore

@@ -38,6 +38,8 @@ bin/
 
 ### VS Code ###
 .vscode/
+graphify-out/
+.graphify_*.json
 
 ### Mac OS ###
 .DS_Store

.idea/gradle.xml

@@ -12,6 +12,8 @@
             <option value="$PROJECT_DIR$/modules" />
             <option value="$PROJECT_DIR$/modules/api" />
             <option value="$PROJECT_DIR$/modules/core" />
+            <option value="$PROJECT_DIR$/modules/io" />
+            <option value="$PROJECT_DIR$/modules/rule" />
             <option value="$PROJECT_DIR$/modules/ui" />
           </set>
         </option>

.idea/scala_compiler.xml

@@ -5,7 +5,7 @@
       <option name="deprecationWarnings" value="true" />
       <option name="uncheckedWarnings" value="true" />
     </profile>
-    <profile name="Gradle 2" modules="NowChessSystems.modules.core.main,NowChessSystems.modules.core.scoverage,NowChessSystems.modules.core.test,NowChessSystems.modules.ui.main,NowChessSystems.modules.ui.scoverage,NowChessSystems.modules.ui.test">
+    <profile name="Gradle 2" modules="NowChessSystems.modules.core.main,NowChessSystems.modules.core.scoverage,NowChessSystems.modules.core.test,NowChessSystems.modules.io.main,NowChessSystems.modules.io.scoverage,NowChessSystems.modules.io.test,NowChessSystems.modules.rule.main,NowChessSystems.modules.rule.scoverage,NowChessSystems.modules.rule.test,NowChessSystems.modules.ui.main,NowChessSystems.modules.ui.scoverage,NowChessSystems.modules.ui.test">
       <option name="deprecationWarnings" value="true" />
       <option name="uncheckedWarnings" value="true" />
       <parameters>

.scalafix.conf

@@ -0,0 +1,15 @@
+rules = [
+  DisableSyntax,
+  LeakingImplicitClassVal,
+  NoValInForComprehension,
+  ProcedureSyntax,
+]
+
+DisableSyntax.noVars        = true
+DisableSyntax.noThrows      = true
+DisableSyntax.noNulls       = true
+DisableSyntax.noReturns     = true
+DisableSyntax.noAsInstanceOf = true
+DisableSyntax.noIsInstanceOf = true
+DisableSyntax.noXml         = true
+DisableSyntax.noFinalize    = true

.scalafmt.conf

@@ -0,0 +1,8 @@
+version = 3.8.1
+runner.dialect = scala3
+maxColumn = 120
+indent.main = 2
+align.preset = more
+trailingCommas = always
+rewrite.rules = [SortImports, RedundantBraces]
+rewrite.scala3.convertToNewSyntax = true

AGENTS.md

@@ -0,0 +1,21 @@
+# Project Context
+
+This is a scala project using raw-http.
+
+Middleware includes: custom.
+
+High-impact files (most imported, changes here affect many other files):
+- modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala (imported by 50 files)
+- modules/api/src/main/scala/de/nowchess/api/board/Square.scala (imported by 33 files)
+- modules/api/src/main/scala/de/nowchess/api/board/Color.scala (imported by 30 files)
+- modules/api/src/main/scala/de/nowchess/api/move/Move.scala (imported by 29 files)
+- modules/api/src/main/scala/de/nowchess/api/board/Board.scala (imported by 19 files)
+- modules/api/src/main/scala/de/nowchess/api/board/PieceType.scala (imported by 18 files)
+- modules/rule/src/main/scala/de/nowchess/rules/sets/DefaultRules.scala (imported by 17 files)
+- modules/api/src/main/scala/de/nowchess/api/board/Piece.scala (imported by 15 files)
+
+Required environment variables (no defaults):
+- STOCKFISH_PATH (modules/bot/python/nnue.py)
+
+Read .codesight/wiki/index.md for orientation (WHERE things live). Then read actual source files before implementing. Wiki articles are navigation aids, not implementation guides.
+Read .codesight/CODESIGHT.md for the complete AI context map including all routes, schema, components, libraries, config, middleware, and dependency graph.

ARABIAN CHESS/license.txt

@@ -0,0 +1,7 @@
+YOU CAN:
+- Edit and use the asset in any commercial  or non commercial project 
+- Use the asset in any commercial  or non commercial project
+
+YOU CAN'T:
+- Resell or distribute the asset to others
+- Edit and resell the asset to others - - Credits required using This link: https://fatman200.itch.io/

CLAUDE.md

@@ -1,58 +1,95 @@
-# CLAUDE.md — NowChessSystems
+# Now-Chess
 
-## Stack
-Scala 3.5.x · Quarkus + quarkus-scala3 · Hibernate/Jakarta · Lanterna TUI · K8s + ArgoCD + Kargo · Frontend TBD (Vite/React/Angular/Vue)
-
-### Memory
-
-Your memory is saved under .claude/memory/MEMORY.md.
-
-## Structure
-```
-build.gradle.kts / settings.gradle.kts   # root; include(":modules:<svc>") per service
-modules/<svc>/build.gradle.kts + src/
-docs/adr/  docs/api/  docs/unresolved.md
-```
-Versions in root `extra["VERSIONS"]`; modules read via `rootProject.extra["VERSIONS"] as Map<String,String>`.
+Scala 3.5.1 · Gradle 9
 
 ## Commands
-```bash
-./gradlew build
-./gradlew :modules:<svc>:build|test
-./gradlew :modules:<svc>:test --tests "de.nowchess.<svc>.<Class>"
+
 ```
-
-## Workflow
-1. **Plan** — restate requirement, list files, flag risks. Proceed unless genuine ambiguity.
-2. **Tests first** — cover only new behaviour.
-3. **Implement** — no scope creep.
-4. **Verify** — check each requirement; confirm green build.
-
-## Scala/Quarkus Rules
-- `given`/`using` only (no `implicit`); `Option`/`Either`/`Try` (no `null`/`.get`)
-- `jakarta.*` only; reactive I/O (`Uni`/`Multi`), no blocking on event loop
-- Always exclude `org.scala-lang:scala-library` from Quarkus BOM
-- Unit tests: `extends AnyFunSuite with Matchers` — no `@Test`, no `: Unit`
-- Integration tests: `@QuarkusTest` + JUnit 5 — `@Test` methods need explicit `: Unit`
-
-## Coverage
-Line = 100% · Branch = 100% · Method = 100% · Regression tests · document exceptions
-Check: `jacoco-reporter/scoverage_coverage_gaps.py modules/{svc}/build/reports/scoverageTest/scoverage.xml`
-⚠️ Use `scoverageTest/`, NOT `scoverage/`.
-
-## Bug Fixing
-Fix failures immediately without asking. After 3 failed attempts → log in `docs/unresolved.md` + surface summary.
-
-## Agents (new service)
-Sequential: architect → scala-implementer → test-writer → gradle-builder → code-reviewer (review only, no self-fix)
-Parallel: only when services are fully independent (no shared contracts/state).
-
-## Unresolved (`docs/unresolved.md`)
-Append only, never delete:
-```
-## [YYYY-MM-DD] <title>
-**Requirement/Bug:** **Root Cause:** **Attempted Fixes:** **Next Step:**
+./clean      # Clear build dirs — only when necessary
+./compile    # Compile all modules — always run
+./test       # Run all tests
+./coverage   # Check coverage
 ```
+Try to stick to these commands for consistency.
 
-## Done Checklist
-- [ ] Plan written · files created/modified · tests green · requirements verified · unresolved logged
+## Modules
+
+| Module | Role | Depends on |
+|--------|------|-----------|
+| `api`  | Model / shared types | (none) |
+| `core` | Primary business logic | api, rule |
+| `rule` | Game rules | api |
+| `io`   | Export formats | api, core |
+| `ui`   | Entrypoint & UI | core, io |
+
+## Style
+
+- Use immutable data and pure functions.
+- Keep functions under 30 lines. If you need "and" to describe it, split it.
+- Keep cyclomatic complexity under 15.
+- Avoid comments. Let names carry intent; comment only non-obvious algorithms.
+- Scan for duplicated logic before finishing. Extract it.
+- Follow default Sonar style for Scala.
+- Use `Option` or `Either` for fallible operations; avoid exceptions for control flow.
+- Naming: types are PascalCase, functions/values are camelCase.
+
+## Code Quality
+
+- **Coverage:** 100% condition coverage required in `api`, `core`, `rule`, `io` (mandatory); `ui` exempt.
+
+### Linters
+
+- **scalafmt** — enforces formatting; run `./gradlew spotlessScalaCheck` to check and `./gradlew spotlessScalaApply` to refactor.
+- **scalafix** — enforces style and detects unused imports/code; run `./gradlew scalafix` to apply rules.
+
+## Architecture Decisions
+
+- **Immutable state as primary model:** GameContext (api) holds board, history, player state — immutable, passed through the system. Each move creates a new GameContext, enabling undo/redo without side effects.
+- **Observer pattern for UI decoupling:** GameEngine publishes move/state events; CommandInvoker queues moves; UI listens to events, not polling. GameEngine never imports UI code.
+- **RuleSet trait encapsulates rules:** Move generation, check, castling, en passant all in RuleSet impl. GameEngine calls rules as a black box; rules don't know about the rest of core.
+
+## Rules
+
+- **Tests are the spec.** Never modify tests to pass; modify requirements or code. Update tests only if requirements change.
+- Never read build folders. Ask permission if needed.
+- Keep this file up to date with any important decisions or conventions.
+
+---
+
+## Instructions for Claude Code
+
+### Two-Step Rule (mandatory)
+**Step 1 — Orient:** Use wiki articles to find WHERE things live.
+**Step 2 — Verify:** Read the actual source files listed in the wiki article BEFORE writing any code.
+
+Wiki articles are structural summaries extracted by AST. They show routes, models, and file locations.
+They do NOT show full function logic, middleware internals, or dynamic runtime behavior.
+**Never write or modify code based solely on wiki content — always read source files first.**
+
+Read in order at session start:
+1. `.codesight/wiki/index.md` — orientation map (~200 tokens)
+2. `.codesight/wiki/overview.md` — architecture overview (~500 tokens)
+3. Domain article (e.g. `.codesight/wiki/auth.md`) → check "Source Files" section → read those files
+4. `.codesight/CODESIGHT.md` — full context map for deep exploration
+
+Routes marked `[inferred]` in wiki articles were detected via regex — verify against source before trusting.
+If any source file shows ⚠ in the wiki, re-run `codesight --wiki` before proceeding.
+
+Or use the codesight MCP server for on-demand queries:
+- `codesight_get_wiki_article` — read a specific wiki article by name
+- `codesight_get_wiki_index` — get the wiki index
+- `codesight_get_summary` — quick project overview
+- `codesight_get_routes --prefix /api/users` — filtered routes
+- `codesight_get_blast_radius --file src/lib/db.ts` — impact analysis before changes
+- `codesight_get_schema --model users` — specific model details
+
+Only open specific files after consulting codesight context. This saves ~16.893 tokens per conversation.
+
+## graphify
+
+This project has a graphify knowledge graph at graphify-out/.
+
+Rules:
+- Before answering architecture or codebase questions, read graphify-out/GRAPH_REPORT.md for god nodes and community structure
+- If graphify-out/wiki/index.md exists, navigate it instead of reading raw files
+- After modifying code files in this session, run `python3 -c "from graphify.watch import _rebuild_code; from pathlib import Path; _rebuild_code(Path('.'))"` to keep the graph current

build.gradle.kts

@@ -1,5 +1,8 @@
 plugins {
     id("org.sonarqube") version "7.2.3.7755"
+    id("org.scoverage") version "8.1" apply false
+    id("com.diffplug.spotless") version "8.4.0" apply false
+    id("io.github.cosmicsilence.scalafix") version "0.2.6" apply false
 }
 
 group = "de.nowchess"
@@ -28,7 +31,38 @@ val versions = mapOf(
     "SCALA_LIBRARY"         to "2.13.18",
     "SCALATEST"             to "3.2.19",
     "SCALATEST_JUNIT"       to "0.1.11",
-    "SCOVERAGE"             to "2.1.1"
+    "SCOVERAGE"             to "2.1.1",
+    "SCALAFX"               to "21.0.0-R32",
+    "JAVAFX"                to "21.0.1",
+    "JUNIT_BOM"             to "5.13.4",
+    "SCALA_PARSER_COMBINATORS" to "2.4.0",
+    "FASTPARSE"             to "3.0.2",
+    "JACKSON"               to "2.17.2",
+    "JACKSON_SCALA"         to "2.17.2"
 )
 extra["VERSIONS"] = versions
 
+subprojects {
+    apply(plugin = "com.diffplug.spotless")
+
+    pluginManager.withPlugin("scala") {
+        configure<com.diffplug.gradle.spotless.SpotlessExtension> {
+            scala {
+                scalafmt().configFile(rootProject.file(".scalafmt.conf"))
+            }
+        }
+
+        apply(plugin = "io.github.cosmicsilence.scalafix")
+        configure<io.github.cosmicsilence.scalafix.ScalafixExtension> {
+            configFile.set(rootProject.file(".scalafix.conf"))
+        }
+
+        // Disable SemanticDB config for the scoverage source set — it sets -sourceroot to
+        // the root project dir, which conflicts with scoverage's own -sourceroot and causes
+        // reportTestScoverage to fail with "No source root found".
+        tasks.matching { it.name in setOf("configSemanticDBScoverage", "checkScalafixScoverage", "checkScalafixTest") }.configureEach {
+            enabled = false
+        }
+    }
+}
+

clean

@@ -0,0 +1,4 @@
+#! /usr/bin/env bash
+set -euo pipefail
+
+./gradlew clean

compile

@@ -0,0 +1,4 @@
+#! /usr/bin/env bash
+set -euo pipefail
+
+./gradlew classes

coverage

@@ -0,0 +1,10 @@
+#! /usr/bin/env bash
+set -euo pipefail
+
+./gradlew test
+
+if [ "$#" -eq 0 ]; then
+  PYTHONUTF8=1 python3 jacoco-reporter/scoverage_coverage_gaps.py
+else
+  PYTHONUTF8=1 python3 jacoco-reporter/scoverage_coverage_gaps.py "modules/$1/build/reports/scoverageTest/scoverage.xml"
+fi

docs/api-spec.yaml

@@ -0,0 +1,776 @@
+openapi: 3.0.3
+info:
+  title: NowChess API
+  description: |
+    REST API for the NowChess application. Designed to feel familiar to users
+    of the [lichess API](https://lichess.org/api).
+
+    ## Authentication
+    Most endpoints require a Bearer token:
+    ```
+    Authorization: Bearer <token>
+    ```
+    Authentication is reserved for future implementation — endpoints are currently
+    open unless noted otherwise.
+
+    ## Move notation
+    Moves are expressed in **UCI notation**: `{from}{to}[promotion]`
+    - Normal move: `e2e4`
+    - Capture: `d5e6`
+    - Promotion: `e7e8q` (q=queen, r=rook, b=bishop, n=knight)
+    - Castling: `e1g1` (kingside white), `e1c1` (queenside white)
+
+    ## Streaming
+    Endpoints that support streaming return **NDJSON** (newline-delimited JSON).
+    Request them with:
+    ```
+    Accept: application/x-ndjson
+    ```
+    Each line of the response is a complete JSON object. Empty lines are
+    keep-alive heartbeats.
+
+    ## Rate limiting
+    Requests that exceed the rate limit receive `429 Too Many Requests`.
+    Honour the `Retry-After` response header and wait before retrying.
+  version: 1.0.0
+  contact:
+    name: NowChess
+  license:
+    name: MIT
+
+servers:
+  - url: http://localhost:8080
+    description: Local development server
+
+tags:
+  - name: game
+    description: Create and manage chess games
+  - name: move
+    description: Make moves and navigate game history
+  - name: draw
+    description: Draw offers and claims
+  - name: import
+    description: Load a game from FEN or PGN
+  - name: export
+    description: Export a game as FEN or PGN
+
+paths:
+
+  # ---------------------------------------------------------------------------
+  # Game lifecycle
+  # ---------------------------------------------------------------------------
+
+  /api/board/game:
+    post:
+      operationId: createGame
+      tags: [game]
+      summary: Create a new game
+      description: |
+        Creates a new chess game starting from the initial position.
+        Returns the full game state including the generated `gameId`.
+      security:
+        - bearerAuth: []
+      requestBody:
+        required: false
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/CreateGameRequest'
+      responses:
+        '201':
+          description: Game created
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GameFull'
+        '400':
+          $ref: '#/components/responses/BadRequest'
+        '401':
+          $ref: '#/components/responses/Unauthorized'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+  /api/board/game/{gameId}:
+    get:
+      operationId: getGame
+      tags: [game]
+      summary: Get game state
+      description: Returns the full current state of a game.
+      security:
+        - bearerAuth: []
+      parameters:
+        - $ref: '#/components/parameters/gameId'
+      responses:
+        '200':
+          description: Current game state
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GameFull'
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+  /api/board/game/{gameId}/stream:
+    get:
+      operationId: streamGame
+      tags: [game]
+      summary: Stream game events
+      description: |
+        Opens a persistent NDJSON stream for a game. The first object sent is
+        a `gameFull` event containing the complete game state. Subsequent
+        objects are `gameState` events sent whenever the game changes (move
+        made, draw offered, game over, etc.).
+
+        Empty lines are heartbeats to keep the connection alive.
+
+        Connect with:
+        ```
+        Accept: application/x-ndjson
+        ```
+      security:
+        - bearerAuth: []
+      parameters:
+        - $ref: '#/components/parameters/gameId'
+      responses:
+        '200':
+          description: NDJSON event stream
+          content:
+            application/x-ndjson:
+              schema:
+                oneOf:
+                  - $ref: '#/components/schemas/GameFullEvent'
+                  - $ref: '#/components/schemas/GameStateEvent'
+                  - $ref: '#/components/schemas/ErrorEvent'
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+  /api/board/game/{gameId}/resign:
+    post:
+      operationId: resignGame
+      tags: [game]
+      summary: Resign the game
+      description: The active player resigns. The game ends immediately.
+      security:
+        - bearerAuth: []
+      parameters:
+        - $ref: '#/components/parameters/gameId'
+      responses:
+        '200':
+          description: Resignation accepted
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/OkResponse'
+        '400':
+          $ref: '#/components/responses/BadRequest'
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+  # ---------------------------------------------------------------------------
+  # Move-making
+  # ---------------------------------------------------------------------------
+
+  /api/board/game/{gameId}/move/{uci}:
+    post:
+      operationId: makeMove
+      tags: [move]
+      summary: Make a move
+      description: |
+        Submit a move in UCI notation. The move must be legal for the side
+        currently to move.
+
+        For promotion moves include the target piece as the fifth character:
+        `e7e8q`, `a2a1r`, etc.
+
+        If the move results in a pawn reaching the back rank and no promotion
+        character is supplied, the game enters `promotionPending` status and
+        the move is not yet applied — resubmit with the promotion character.
+      security:
+        - bearerAuth: []
+      parameters:
+        - $ref: '#/components/parameters/gameId'
+        - name: uci
+          in: path
+          required: true
+          description: Move in UCI notation (e.g. `e2e4`, `e7e8q`)
+          schema:
+            type: string
+            pattern: '^[a-h][1-8][a-h][1-8][qrbn]?$'
+            example: e2e4
+      responses:
+        '200':
+          description: Move applied — returns updated game state
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GameState'
+        '400':
+          $ref: '#/components/responses/BadRequest'
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+  /api/board/game/{gameId}/moves:
+    get:
+      operationId: getLegalMoves
+      tags: [move]
+      summary: Get legal moves
+      description: |
+        Returns all legal moves for the side currently to move.
+        Optionally filter to moves originating from a single square.
+      security:
+        - bearerAuth: []
+      parameters:
+        - $ref: '#/components/parameters/gameId'
+        - name: square
+          in: query
+          required: false
+          description: Filter to moves from this square (e.g. `e2`)
+          schema:
+            type: string
+            pattern: '^[a-h][1-8]$'
+            example: e2
+      responses:
+        '200':
+          description: List of legal moves
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/LegalMovesResponse'
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+  /api/board/game/{gameId}/undo:
+    post:
+      operationId: undoMove
+      tags: [move]
+      summary: Undo the last move
+      description: Reverts the most recent move. Returns the updated game state.
+      security:
+        - bearerAuth: []
+      parameters:
+        - $ref: '#/components/parameters/gameId'
+      responses:
+        '200':
+          description: Move undone
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GameState'
+        '400':
+          description: No moves to undo
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ApiError'
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+  /api/board/game/{gameId}/redo:
+    post:
+      operationId: redoMove
+      tags: [move]
+      summary: Redo a previously undone move
+      description: Re-applies the next move in the undo stack. Returns the updated game state.
+      security:
+        - bearerAuth: []
+      parameters:
+        - $ref: '#/components/parameters/gameId'
+      responses:
+        '200':
+          description: Move redone
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GameState'
+        '400':
+          description: No moves to redo
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ApiError'
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+  # ---------------------------------------------------------------------------
+  # Draw handling
+  # ---------------------------------------------------------------------------
+
+  /api/board/game/{gameId}/draw/{action}:
+    post:
+      operationId: drawAction
+      tags: [draw]
+      summary: Offer, accept, decline, or claim a draw
+      description: |
+        Perform a draw-related action:
+
+        | Action    | Description |
+        |-----------|-------------|
+        | `offer`   | Offer a draw to the opponent |
+        | `accept`  | Accept the opponent's draw offer |
+        | `decline` | Decline the opponent's draw offer |
+        | `claim`   | Claim a draw under the fifty-move rule (only valid when `status` is `fiftyMoveAvailable`) |
+      security:
+        - bearerAuth: []
+      parameters:
+        - $ref: '#/components/parameters/gameId'
+        - name: action
+          in: path
+          required: true
+          schema:
+            type: string
+            enum: [offer, accept, decline, claim]
+      responses:
+        '200':
+          description: Action accepted
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/OkResponse'
+        '400':
+          $ref: '#/components/responses/BadRequest'
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+  # ---------------------------------------------------------------------------
+  # Import
+  # ---------------------------------------------------------------------------
+
+  /api/board/game/import/fen:
+    post:
+      operationId: importFen
+      tags: [import]
+      summary: Load a position from FEN
+      description: |
+        Creates a new game from a FEN string. The game starts at the position
+        described by the FEN; move history prior to that position is not
+        available.
+      security:
+        - bearerAuth: []
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/ImportFenRequest'
+      responses:
+        '201':
+          description: Game created from FEN
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GameFull'
+        '400':
+          $ref: '#/components/responses/BadRequest'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+  /api/board/game/import/pgn:
+    post:
+      operationId: importPgn
+      tags: [import]
+      summary: Load a game from PGN
+      description: |
+        Creates a new game by replaying all moves in a PGN string. The game
+        starts at the position after the final move in the PGN; undo is
+        available for every replayed move.
+      security:
+        - bearerAuth: []
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/ImportPgnRequest'
+      responses:
+        '201':
+          description: Game created from PGN
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GameFull'
+        '400':
+          $ref: '#/components/responses/BadRequest'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+  # ---------------------------------------------------------------------------
+  # Export
+  # ---------------------------------------------------------------------------
+
+  /api/board/game/{gameId}/export/fen:
+    get:
+      operationId: exportFen
+      tags: [export]
+      summary: Export current position as FEN
+      description: Returns the FEN string representing the current board position.
+      security:
+        - bearerAuth: []
+      parameters:
+        - $ref: '#/components/parameters/gameId'
+      responses:
+        '200':
+          description: FEN string
+          content:
+            text/plain:
+              schema:
+                type: string
+                example: rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+  /api/board/game/{gameId}/export/pgn:
+    get:
+      operationId: exportPgn
+      tags: [export]
+      summary: Export game as PGN
+      description: Returns the full PGN for the game including headers and move text.
+      security:
+        - bearerAuth: []
+      parameters:
+        - $ref: '#/components/parameters/gameId'
+      responses:
+        '200':
+          description: PGN text
+          content:
+            application/x-chess-pgn:
+              schema:
+                type: string
+                example: |
+                  [Event "NowChess game"]
+                  [White "Player1"]
+                  [Black "Player2"]
+                  [Result "*"]
+
+                  1. e4 e5 2. Nf3 *
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '429':
+          $ref: '#/components/responses/TooManyRequests'
+
+# =============================================================================
+# Components
+# =============================================================================
+
+components:
+
+  securitySchemes:
+    bearerAuth:
+      type: http
+      scheme: bearer
+      description: 'Personal access token — `Authorization: Bearer <token>`'
+
+  parameters:
+    gameId:
+      name: gameId
+      in: path
+      required: true
+      description: 8-character alphanumeric game ID (e.g. `Qa7FJNk2`)
+      schema:
+        type: string
+        pattern: '^[A-Za-z0-9]{8}$'
+        example: Qa7FJNk2
+
+  responses:
+    BadRequest:
+      description: Invalid input
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/ApiError'
+    Unauthorized:
+      description: Missing or invalid authentication token
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/ApiError'
+    NotFound:
+      description: Game not found
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/ApiError'
+    TooManyRequests:
+      description: Rate limit exceeded — see `Retry-After` header
+      headers:
+        Retry-After:
+          description: Seconds to wait before retrying
+          schema:
+            type: integer
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/ApiError'
+
+  schemas:
+
+    # -------------------------------------------------------------------------
+    # Requests
+    # -------------------------------------------------------------------------
+
+    CreateGameRequest:
+      type: object
+      description: Parameters for creating a new game. All fields are optional.
+      properties:
+        white:
+          $ref: '#/components/schemas/PlayerInfo'
+        black:
+          $ref: '#/components/schemas/PlayerInfo'
+
+    ImportFenRequest:
+      type: object
+      required: [fen]
+      properties:
+        fen:
+          type: string
+          description: Complete FEN string (6 fields)
+          example: rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
+        white:
+          $ref: '#/components/schemas/PlayerInfo'
+        black:
+          $ref: '#/components/schemas/PlayerInfo'
+
+    ImportPgnRequest:
+      type: object
+      required: [pgn]
+      properties:
+        pgn:
+          type: string
+          description: PGN text (headers and move list)
+          example: "1. e4 e5 2. Nf3 Nc6 *"
+
+    # -------------------------------------------------------------------------
+    # Game state
+    # -------------------------------------------------------------------------
+
+    GameFull:
+      type: object
+      description: Complete game information including players and current state.
+      required: [gameId, white, black, state]
+      properties:
+        gameId:
+          type: string
+          description: Unique 8-character game identifier
+          example: Qa7FJNk2
+        white:
+          $ref: '#/components/schemas/PlayerInfo'
+        black:
+          $ref: '#/components/schemas/PlayerInfo'
+        state:
+          $ref: '#/components/schemas/GameState'
+
+    GameState:
+      type: object
+      description: |
+        The current game state. Included in `GameFull` and returned by move
+        endpoints and stream events.
+      required: [fen, pgn, turn, status, moves, undoAvailable, redoAvailable]
+      properties:
+        fen:
+          type: string
+          description: FEN string for the current position
+          example: rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1
+        pgn:
+          type: string
+          description: PGN move text for the full game so far
+          example: "1. e4"
+        turn:
+          type: string
+          enum: [white, black]
+          description: The side to move
+        status:
+          $ref: '#/components/schemas/GameStatus'
+        winner:
+          type: string
+          enum: [white, black]
+          description: Set when `status` is `checkmate` or `resign`
+          nullable: true
+        moves:
+          type: array
+          description: All moves played so far, in UCI notation
+          items:
+            type: string
+          example: [e2e4, e7e5, g1f3]
+        undoAvailable:
+          type: boolean
+          description: Whether `POST /undo` is currently valid
+        redoAvailable:
+          type: boolean
+          description: Whether `POST /redo` is currently valid
+
+    GameStatus:
+      type: string
+      description: |
+        Current game status:
+
+        | Value | Meaning |
+        |-------|---------|
+        | `started` | Game in progress, no special condition |
+        | `check` | Side to move is in check |
+        | `checkmate` | Side to move is checkmated — game over |
+        | `stalemate` | Side to move has no legal moves, not in check — game over (draw) |
+        | `resign` | A player resigned — game over |
+        | `draw` | Draw agreed or claimed — game over |
+        | `drawOffered` | Waiting for the opponent to accept or decline a draw offer |
+        | `fiftyMoveAvailable` | Fifty-move rule threshold reached; active player may claim draw |
+        | `promotionPending` | A pawn reached the back rank; awaiting promotion piece selection |
+        | `insufficientMaterial` | Neither side has enough pieces to deliver checkmate — game over (draw) |
+      enum:
+        - started
+        - check
+        - checkmate
+        - stalemate
+        - resign
+        - draw
+        - drawOffered
+        - fiftyMoveAvailable
+        - promotionPending
+        - insufficientMaterial
+
+    # -------------------------------------------------------------------------
+    # Moves
+    # -------------------------------------------------------------------------
+
+    LegalMovesResponse:
+      type: object
+      required: [moves]
+      properties:
+        moves:
+          type: array
+          items:
+            $ref: '#/components/schemas/LegalMove'
+
+    LegalMove:
+      type: object
+      required: [from, to, uci, moveType]
+      properties:
+        from:
+          type: string
+          description: Origin square in algebraic notation
+          example: e2
+        to:
+          type: string
+          description: Destination square in algebraic notation
+          example: e4
+        uci:
+          type: string
+          description: Full move in UCI notation
+          example: e2e4
+        moveType:
+          $ref: '#/components/schemas/MoveType'
+        promotion:
+          type: string
+          enum: [queen, rook, bishop, knight]
+          description: Target piece for promotion moves
+          nullable: true
+
+    MoveType:
+      type: string
+      description: Classification of the move
+      enum:
+        - normal
+        - capture
+        - castleKingside
+        - castleQueenside
+        - enPassant
+        - promotion
+
+    # -------------------------------------------------------------------------
+    # Streaming events
+    # -------------------------------------------------------------------------
+
+    GameFullEvent:
+      type: object
+      description: |
+        First event on a game stream. Contains the complete game snapshot.
+      required: [type, game]
+      properties:
+        type:
+          type: string
+          enum: [gameFull]
+        game:
+          $ref: '#/components/schemas/GameFull'
+
+    GameStateEvent:
+      type: object
+      description: |
+        Emitted on a game stream whenever the game state changes (move played,
+        draw offered, game over, etc.).
+      required: [type, state]
+      properties:
+        type:
+          type: string
+          enum: [gameState]
+        state:
+          $ref: '#/components/schemas/GameState'
+
+    ErrorEvent:
+      type: object
+      description: Emitted on a game stream when an error occurs.
+      required: [type, error]
+      properties:
+        type:
+          type: string
+          enum: [error]
+        error:
+          $ref: '#/components/schemas/ApiError'
+
+    # -------------------------------------------------------------------------
+    # Shared types
+    # -------------------------------------------------------------------------
+
+    PlayerInfo:
+      type: object
+      required: [id, displayName]
+      properties:
+        id:
+          type: string
+          description: Unique player identifier
+          example: player1
+        displayName:
+          type: string
+          description: Human-readable display name
+          example: Alice
+
+    OkResponse:
+      type: object
+      required: [ok]
+      properties:
+        ok:
+          type: boolean
+          enum: [true]
+
+    ApiError:
+      type: object
+      required: [code, message]
+      properties:
+        code:
+          type: string
+          description: Machine-readable error code
+          example: INVALID_MOVE
+        message:
+          type: string
+          description: Human-readable error description
+          example: e2e5 is not a legal move
+        field:
+          type: string
+          description: Request field that caused the error, if applicable
+          example: uci
+          nullable: true

docs/unresolved.md

@@ -1,20 +0,0 @@
-## [2026-03-31] Unreachable code blocking 100% statement coverage
-
-**Requirement/Bug:** Reach 100% statement coverage in core module.
-
-**Root Cause:** 4 remaining uncovered statements (99.6% coverage) are unreachable code:
-1. **PgnParser.scala:160** (`case _ => None` in extractPromotion) - Regex `=([QRBN])` only matches those 4 characters; fallback case can never execute
-2. **GameHistory.scala:29** (`addMove$default$4` compiler-generated method) - Method overload 3 without defaults shadows the 4-param version, making promotionPiece default accessor unreachable
-3. **GameEngine.scala:201-202** (`case _` in completePromotion) - GameController.completePromotion always returns one of 4 expected MoveResult types; catch-all is defensive code
-
-**Attempted Fixes:**
-1. Added comprehensive PGN parsing tests (all 4 promotion types) - PgnParser improved from 95.8% to 99.4%
-2. Added GameHistory tests using named parameters - hit `addMove$default$3` (castleSide) but not `$default$4` (promotionPiece)
-3. Named parameter approach: `addMove(from=..., to=..., promotionPiece=...)` triggers 4-param with castleSide default ✓
-4. Positional approach: `addMove(f, t, None, None)` requires all 4 args (explicit, no defaults used) - doesn't hit $default$4
-5. Root issue: Scala's overload resolution prefers more-specific non-default overloads (2-param, 3-param) over the 4-param with defaults
-
-**Recommendation:** 99.6% (1029/1033) is maximum achievable without refactoring method overloads. Unreachable code design patterns:
-- **Pattern 1 (unreachable regex fallback):** Defensive pattern match against exhaustive regex
-- **Pattern 2 (overshadowed defaults):** Method overloads shadow default parameters in parent signature
-- **Pattern 3 (defensive catch-all):** Error handling for impossible external API returns

jacoco-reporter/scoverage_coverage_gaps.py

@@ -19,6 +19,9 @@ Usage:
     python scoverage_coverage_gaps.py <scoverage.xml> --output agent   (default)
     python scoverage_coverage_gaps.py <scoverage.xml> --package-filter de.nowchess.chess.controller
     python scoverage_coverage_gaps.py <scoverage.xml> --min-coverage 80
+    python scoverage_coverage_gaps.py                                 (default: scans ./modules)
+    python scoverage_coverage_gaps.py --modules-dir ./services
+    python scoverage_coverage_gaps.py <scoverage.xml>
 """
 
 import xml.etree.ElementTree as ET
@@ -26,7 +29,8 @@ import sys
 import argparse
 import json
 import re
-from pathlib import Path, PureWindowsPath
+import glob
+from pathlib import Path
 from dataclasses import dataclass, field
 from typing import Optional
 
@@ -112,7 +116,6 @@ class ClassGap:
     @property
     def uncovered_branch_lines(self) -> list[int]:
         """Lines that are branch points and have at least one uncovered branch statement."""
-        # Group branch statements by line; a line is "partial" if some covered, some not
         from collections import defaultdict
         by_line: dict[int, list[Statement]] = defaultdict(list)
         for s in self.statements:
@@ -120,10 +123,7 @@ class ClassGap:
                 by_line[s.line].append(s)
         partial = []
         for line, stmts in by_line.items():
-            has_covered = any(s.is_covered for s in stmts)
-            has_uncovered = any(s.is_uncovered for s in stmts)
-            # Report line if any branch arm is uncovered
-            if has_uncovered:
+            if any(s.is_uncovered for s in stmts):
                 partial.append(line)
         return sorted(partial)
 
@@ -169,20 +169,10 @@ class ClassGap:
 # ---------------------------------------------------------------------------
 
 def _normalise_source(raw: str) -> str:
-    """
-    Convert an absolute Windows or Unix source path from the XML into a
-    relative src/main/scala/… path for agent consumption.
-
-    Strategy:
-      1. Replace Windows backslashes.
-      2. Find the 'src/' anchor and take everything from there.
-      3. Fall back to the package-derived path if no anchor found.
-    """
     normalised = raw.replace("\\", "/")
     match = re.search(r"(src/(?:main|test)/scala/.+)", normalised)
     if match:
         return match.group(1)
-    # Fallback: just the filename portion
     return normalised.split("/")[-1]
 
 
@@ -190,11 +180,10 @@ def _normalise_source(raw: str) -> str:
 # Parser
 # ---------------------------------------------------------------------------
 
-def parse_scoverage_xml(xml_path: str) -> list[ClassGap]:
+def parse_scoverage_xml(xml_path: str) -> tuple[dict, list[ClassGap]]:
     tree = ET.parse(xml_path)
     root = tree.getroot()
 
-    # ── Authoritative project-level totals from <scoverage> root element ──────
     project_stats = {
         "total_statements":    int(root.get("statement-count", 0)),
         "covered_statements":  int(root.get("statements-invoked", 0)),
@@ -202,17 +191,16 @@ def parse_scoverage_xml(xml_path: str) -> list[ClassGap]:
         "branch_coverage_pct": float(root.get("branch-rate", 0.0)),
     }
     project_stats["missed_statements"] = (
-        project_stats["total_statements"] - project_stats["covered_statements"]
+            project_stats["total_statements"] - project_stats["covered_statements"]
     )
 
-    class_map: dict[str, ClassGap] = {}   # full-class-name → ClassGap
+    class_map: dict[str, ClassGap] = {}
 
     for package in root.findall("packages/package"):
         for cls_elem in package.findall("classes/class"):
             class_name = cls_elem.get("name", "")
             filename   = cls_elem.get("filename", "")
 
-            # Authoritative per-class totals from <class> attributes
             cls_total     = int(cls_elem.get("statement-count", 0))
             cls_invoked   = int(cls_elem.get("statements-invoked", 0))
             cls_stmt_rate = float(cls_elem.get("statement-rate", 0.0))
@@ -221,11 +209,8 @@ def parse_scoverage_xml(xml_path: str) -> list[ClassGap]:
             for method_elem in cls_elem.findall("methods/method"):
                 method_name = method_elem.get("name", "")
 
-                # Authoritative per-method totals from <method> attributes
-                m_total     = int(method_elem.get("statement-count", 0))
-                m_invoked   = int(method_elem.get("statements-invoked", 0))
-                m_stmt_rate = float(method_elem.get("statement-rate", 0.0))
-                m_br_rate   = float(method_elem.get("branch-rate", 0.0))
+                m_total   = int(method_elem.get("statement-count", 0))
+                m_invoked = int(method_elem.get("statements-invoked", 0))
 
                 for stmt_elem in method_elem.findall("statements/statement"):
                     raw_source = stmt_elem.get("source", filename)
@@ -257,7 +242,6 @@ def parse_scoverage_xml(xml_path: str) -> list[ClassGap]:
                         method=method_name,
                     ))
 
-                # Register method-level gap using authoritative XML stats
                 cg = next(
                     (v for v in class_map.values() if v.class_name == class_name),
                     None,
@@ -268,7 +252,6 @@ def parse_scoverage_xml(xml_path: str) -> list[ClassGap]:
                 uncov_lines        = sorted({s.line for s in active if s.is_uncovered})
                 uncov_branch_lines = sorted({s.line for s in active if s.is_branch and s.is_uncovered})
                 if uncov_lines or uncov_branch_lines:
-                    # Count branches from statement-level data (not in method XML attrs)
                     total_b = sum(1 for s in active if s.is_branch)
                     cov_b   = sum(1 for s in active if s.is_branch and s.is_covered)
                     mg = MethodGap(
@@ -282,7 +265,6 @@ def parse_scoverage_xml(xml_path: str) -> list[ClassGap]:
                     )
                     cg.method_gaps.append(mg)
 
-    # ── Project stats injected so formatters never recount from statements ────
     return project_stats, [cg for cg in class_map.values() if cg.has_gaps]
 
 
@@ -310,103 +292,60 @@ def _compact_ranges(numbers: list[int]) -> str:
 # Formatters
 # ---------------------------------------------------------------------------
 
-def _pct_bar(pct: float, width: int = 20) -> str:
-    """Render a compact ASCII progress bar, e.g. [████░░░░░░░░░░░░░░░░] 23.5%"""
-    filled = round(pct / 100 * width)
-    bar = "█" * filled + "░" * (width - filled)
-    return f"[{bar}] {pct:.1f}%"
-
-
 def format_agent(project_stats: dict, classes: list[ClassGap]) -> str:
+    """
+    Compact agent format — optimised for low token count.
+    Emits only actionable gaps: file path, uncovered lines, branch-gap lines,
+    and a per-method breakdown. No ASCII bars, no redundant tables.
+    """
     lines: list[str] = []
-    lines.append("# scoverage Coverage Gaps — Agent Action Report")
-    lines.append("")
 
-    # ---- Project-level totals (authoritative from <scoverage> root element) ----
-    total_stmts      = project_stats["total_statements"]
-    covered_stmts    = project_stats["covered_statements"]
-    missed_stmts     = project_stats["missed_statements"]
+    total_stmts        = project_stats["total_statements"]
+    covered_stmts      = project_stats["covered_statements"]
+    missed_stmts       = project_stats["missed_statements"]
     overall_stmt_pct   = project_stats["stmt_coverage_pct"]
     overall_branch_pct = project_stats["branch_coverage_pct"]
-    total_branch_lines = sum(len(c.uncovered_branch_lines) for c in classes)
-    # Branch totals: count from statement data (scoverage root has no branch count attr)
-    total_branches   = sum(c.total_branches for c in classes)
-    covered_branches = sum(c.covered_branches for c in classes)
-    missed_branches  = sum(c.missed_branches for c in classes)
+    total_branches     = sum(c.total_branches for c in classes)
+    covered_branches   = sum(c.covered_branches for c in classes)
+    missed_branches    = total_branches - covered_branches
 
-    lines.append("## Project Coverage Summary")
-    lines.append("")
-    lines.append(f"| Metric            | Covered | Total | Missed | Coverage |")
-    lines.append(f"|-------------------|---------|-------|--------|----------|")
-    lines.append(f"| Statements        | {covered_stmts:>7} | {total_stmts:>5} | {missed_stmts:>6} | {_pct_bar(overall_stmt_pct)} |")
-    lines.append(f"| Branch paths      | {covered_branches:>7} | {total_branches:>5} | {missed_branches:>6} | {_pct_bar(overall_branch_pct)} |")
-    lines.append(f"| Files with gaps   | {'—':>7} | {len(classes):>5} | {'—':>6} | {'—'} |")
-    lines.append(f"| Lines w/ br. gaps | {'—':>7} | {total_branch_lines:>5} | {'—':>6} | {'—'} |")
-    lines.append("")
-    lines.append("---")
-    lines.append("")
-    lines.append("## Files Requiring Tests")
-    lines.append("")
-    lines.append("> Each entry lists the SOURCE FILE PATH, uncovered LINE NUMBERS,")
-    lines.append("> and the METHODS that contain those gaps.")
-    lines.append("> Write or extend unit/integration tests to exercise these paths.")
+    lines.append("# scoverage Coverage Gaps")
+    lines.append(
+        f"stmt: {overall_stmt_pct:.1f}% ({missed_stmts}/{total_stmts} missed) | "
+        f"branches: {overall_branch_pct:.1f}% ({missed_branches}/{total_branches} missed) | "
+        f"files with gaps: {len(classes)}"
+    )
     lines.append("")
 
     sorted_classes = sorted(classes, key=lambda c: -(c.missed_statements + c.missed_branches))
 
     for cls in sorted_classes:
-        lines.append(f"### `{cls.source_path}`")
-        lines.append(f"**Class**: `{cls.class_name}`")
-        lines.append("")
-        lines.append(f"| Metric       | Covered | Total | Missed | Coverage |")
-        lines.append(f"|--------------|---------|-------|--------|----------|")
-        lines.append(f"| Statements   | {cls.covered_statements:>7} | {cls.total_statements:>5} | {cls.missed_statements:>6} | {_pct_bar(cls.stmt_coverage_pct)} |")
-        if cls.total_branches:
-            lines.append(f"| Branch paths | {cls.covered_branches:>7} | {cls.total_branches:>5} | {cls.missed_branches:>6} | {_pct_bar(cls.branch_coverage_pct)} |")
-        lines.append("")
-
-        uncov = cls.all_uncovered_lines
-        if uncov:
-            lines.append("#### ❌ Uncovered Statements")
-            lines.append(f"Lines never executed: `{_compact_ranges(uncov)}`")
-            lines.append("")
-
+        uncov        = cls.all_uncovered_lines
         branch_lines = cls.uncovered_branch_lines
-        if branch_lines:
-            lines.append("#### ⚠️  Missing Branch Coverage (Conditional Paths)")
-            lines.append(f"Lines where not all conditional paths are taken: `{_compact_ranges(branch_lines)}`")
-            lines.append("")
+
+        lines.append(f"## {cls.source_path}")
+        lines.append(
+            f"stmt: {cls.stmt_coverage_pct:.1f}% ({cls.missed_statements} missed)"
+            + (f" | branches: {cls.branch_coverage_pct:.1f}% ({cls.missed_branches} missed)"
+               if cls.total_branches else "")
+        )
+        if uncov:
+            lines.append(f"uncovered lines: {_compact_ranges(uncov)}")
+        only_branch = [l for l in branch_lines if l not in cls.all_uncovered_lines]
+        if only_branch:
+            lines.append(f"partial branches: {_compact_ranges(only_branch)}")
 
         if cls.method_gaps:
-            lines.append("#### Methods with Gaps")
-            lines.append("")
-            lines.append("| Method | Stmt Coverage | Branch Coverage | Uncovered Lines | Branch Gap Lines |")
-            lines.append("|--------|--------------|-----------------|-----------------|------------------|")
+            lines.append("methods:")
             for mg in cls.method_gaps:
-                stmt_cell   = f"{_pct_bar(mg.stmt_coverage_pct, 10)} ({mg.total_statements - mg.covered_statements}/{mg.total_statements} missed)"
-                branch_cell = f"{_pct_bar(mg.branch_coverage_pct, 10)} ({mg.missed_branches}/{mg.total_branches} missed)" if mg.total_branches else "n/a"
-                uncov_cell  = f"`{_compact_ranges(mg.uncovered_lines)}`"        if mg.uncovered_lines        else "—"
-                br_cell     = f"`{_compact_ranges(mg.uncovered_branch_lines)}`" if mg.uncovered_branch_lines else "—"
-                lines.append(f"| `{mg.short_name}` | {stmt_cell} | {branch_cell} | {uncov_cell} | {br_cell} |")
-            lines.append("")
+                parts = [f"  {mg.short_name}"]
+                if mg.uncovered_lines:
+                    parts.append(f"lines={_compact_ranges(mg.uncovered_lines)}")
+                if mg.uncovered_branch_lines:
+                    parts.append(f"branches={_compact_ranges(mg.uncovered_branch_lines)}")
+                lines.append(" ".join(parts))
 
-        lines.append("**Action**: Add tests that exercise the lines/branches listed above.")
         lines.append("")
-        lines.append("---")
-        lines.append("")
-
-    lines.append("## Quick Reference: All Uncovered Locations")
-    lines.append("")
-    lines.append("Copy-paste friendly list for IDE navigation or grep:")
-    lines.append("")
-    lines.append("```")
-    for cls in sorted_classes:
-        for ln in cls.all_uncovered_lines:
-            lines.append(f"{cls.source_path}:{ln}  # uncovered statement")
-        for ln in cls.uncovered_branch_lines:
-            if ln not in cls.all_uncovered_lines:
-                lines.append(f"{cls.source_path}:{ln}  # partial branch")
-    lines.append("```")
 
     return "\n".join(lines)
 
@@ -511,6 +450,87 @@ def format_markdown(project_stats: dict, classes: list[ClassGap]) -> str:
     return "\n".join(lines)
 
 
+# ---------------------------------------------------------------------------
+# Scan-modules mode
+# ---------------------------------------------------------------------------
+
+# Candidate sub-paths within a module directory where scoverage.xml may live.
+_SCOVERAGE_SUBPATHS = [
+    # Gradle / default layout
+    "build/reports/scoverageTest/scoverage.xml",
+    # sbt default (scala version wildcard resolved via glob)
+    "target/scala-*/scoverage-report/scoverage.xml",
+    # Maven / flat layout
+    "target/scoverage-report/scoverage.xml",
+    # Already at root of module
+    "scoverage.xml",
+]
+
+
+def _find_scoverage_xml(module_dir: Path) -> Optional[Path]:
+    """Return the first scoverage.xml found inside *module_dir*, or None."""
+    for pattern in _SCOVERAGE_SUBPATHS:
+        hits = sorted(module_dir.glob(pattern))
+        if hits:
+            return hits[0]
+    return None
+
+
+def format_module_gaps(module_name: str, classes: list[ClassGap], stmt_pct: float) -> str:
+    """
+    One summary line per module. If coverage is not 100%, append an agent hint.
+    """
+    if not classes:
+        return f"[{module_name}] stmt: {stmt_pct:.1f}% ✅"
+
+    line = f"[{module_name}] stmt: {stmt_pct:.1f}%  files_with_gaps: {len(classes)}"
+    if stmt_pct < 100.0:
+        line += f"  # hint: run ./coverage {module_name} for details"
+    return line
+
+
+def run_scan_modules(modules_dir: str, package_filter: Optional[str], min_coverage: float) -> None:
+    base = Path(modules_dir)
+    if not base.is_dir():
+        print(f"ERROR: modules directory not found: {base}", file=sys.stderr)
+        sys.exit(1)
+
+    module_dirs = sorted(p for p in base.iterdir() if p.is_dir())
+    if not module_dirs:
+        print(f"No sub-directories found in {base}", file=sys.stderr)
+        sys.exit(1)
+
+    results: list[str] = []
+    missing: list[str] = []
+
+    for mod_dir in module_dirs:
+        if mod_dir.name.startswith("build"):
+            continue
+        xml_path = _find_scoverage_xml(mod_dir)
+        if xml_path is None:
+            missing.append(mod_dir.name)
+            continue
+
+        project_stats, classes = parse_scoverage_xml(str(xml_path))
+
+        if package_filter:
+            classes = [c for c in classes if c.class_name.startswith(package_filter)]
+        if min_coverage > 0:
+            classes = [c for c in classes if c.stmt_coverage_pct < min_coverage]
+
+        results.append(
+            format_module_gaps(mod_dir.name, classes, project_stats["stmt_coverage_pct"])
+        )
+
+    print("\n".join(results))
+
+    if missing:
+        print(
+            f"\n# Modules without scoverage.xml: {', '.join(missing)}",
+            file=sys.stderr,
+        )
+
+
 # ---------------------------------------------------------------------------
 # Entry point
 # ---------------------------------------------------------------------------
@@ -519,7 +539,13 @@ def main() -> None:
     parser = argparse.ArgumentParser(
         description="Report missing statement & branch coverage from a scoverage XML report."
     )
-    parser.add_argument("xml_file", help="Path to scoverage.xml report file")
+
+    # Positional xml_file is optional when --scan-modules is used
+    parser.add_argument(
+        "xml_file",
+        nargs="?",
+        help="Path to scoverage.xml report file (not required with --scan-modules)",
+    )
     parser.add_argument(
         "--output", "-o",
         choices=["agent", "json", "markdown"],
@@ -537,8 +563,30 @@ def main() -> None:
         default=None,
         help="Only report classes in this package prefix (e.g. de.nowchess.chess.controller)",
     )
+    # ── Scan-modules mode ──────────────────────────────────────────────────
+    parser.add_argument(
+        "--scan-modules",
+        action="store_true",
+        help=(
+            "Scan every sub-directory of --modules-dir for a scoverage.xml "
+            "and print a compact coverage-gaps summary per module."
+        ),
+    )
+    parser.add_argument(
+        "--modules-dir",
+        default="./modules",
+        help="Root directory that contains one sub-directory per module (default: ./modules)",
+    )
+
     args = parser.parse_args()
 
+    # ── Scan-modules path (explicit flag, or default when no xml_file given) ──
+    if args.scan_modules or not args.xml_file:
+        run_scan_modules(args.modules_dir, args.package_filter, args.min_coverage)
+        return
+
+    # ── Single-file path ──────────────────────────────────────────────────
+
     xml_path = Path(args.xml_file)
     if not xml_path.exists():
         print(f"ERROR: File not found: {xml_path}", file=sys.stderr)
@@ -565,4 +613,4 @@ def main() -> None:
 
 
 if __name__ == "__main__":
-    main()
+    main()

jacoco-reporter/test_counter.py

@@ -0,0 +1,12 @@
+import glob,re
+mods=['api','core','io','rule','ui']
+tot=0
+for m in mods:
+ s=0
+ for f in glob.glob(f'modules/{m}/build/test-results/test/TEST-*.xml'):
+  txt=open(f,encoding='utf-8').read(300)
+  m2=re.search(r'tests="(\d+)"',txt)
+  if m2:s+=int(m2.group(1))
+ print(f'{m}: {s}')
+ tot+=s
+print('overall:',tot)

jacoco-reporter/test_gaps.py

@@ -0,0 +1,288 @@
+#!/usr/bin/env python3
+"""
+Test Gap Reporter
+Scans JUnit XML test results under modules/*/build/test-results/*.xml and
+outputs a minimal summary optimised for agent consumption.
+
+Usage:
+    python test_gaps.py                        # scan all modules (default)
+    python test_gaps.py --module chess         # single module
+    python test_gaps.py --module all           # explicit all
+    python test_gaps.py --modules-dir ./modules
+    python test_gaps.py --results-subdir build/test-results
+"""
+
+import xml.etree.ElementTree as ET
+import sys
+import argparse
+from pathlib import Path
+from dataclasses import dataclass, field
+from typing import Optional
+
+
+# ---------------------------------------------------------------------------
+# Data classes
+# ---------------------------------------------------------------------------
+
+@dataclass
+class TestCase:
+    classname: str
+    name: str
+    time: float
+    failure: Optional[str] = None   # message if failed
+    error: Optional[str]   = None   # message if errored
+    skipped: bool          = False
+
+    @property
+    def short_class(self) -> str:
+        return self.classname.split(".")[-1]
+
+    @property
+    def status(self) -> str:
+        if self.failure is not None:
+            return "FAIL"
+        if self.error is not None:
+            return "ERROR"
+        if self.skipped:
+            return "SKIP"
+        return "OK"
+
+
+@dataclass
+class SuiteResult:
+    name: str
+    total: int
+    failures: int
+    errors: int
+    skipped: int
+    time: float
+    cases: list[TestCase] = field(default_factory=list)
+
+    @property
+    def passed(self) -> int:
+        return self.total - self.failures - self.errors - self.skipped
+
+    @property
+    def is_clean(self) -> bool:
+        return self.failures == 0 and self.errors == 0
+
+    @property
+    def bad_cases(self) -> list[TestCase]:
+        return [c for c in self.cases if c.status in ("FAIL", "ERROR")]
+
+    @property
+    def skipped_cases(self) -> list[TestCase]:
+        return [c for c in self.cases if c.skipped]
+
+
+@dataclass
+class ModuleResult:
+    name: str
+    suites: list[SuiteResult] = field(default_factory=list)
+
+    @property
+    def total(self)    -> int: return sum(s.total    for s in self.suites)
+    @property
+    def failures(self) -> int: return sum(s.failures for s in self.suites)
+    @property
+    def errors(self)   -> int: return sum(s.errors   for s in self.suites)
+    @property
+    def skipped(self)  -> int: return sum(s.skipped  for s in self.suites)
+    @property
+    def passed(self)   -> int: return sum(s.passed   for s in self.suites)
+    @property
+    def is_clean(self) -> bool: return self.failures == 0 and self.errors == 0
+
+    @property
+    def bad_cases(self) -> list[TestCase]:
+        return [c for s in self.suites for c in s.bad_cases]
+
+    @property
+    def skipped_cases(self) -> list[TestCase]:
+        return [c for s in self.suites for c in s.skipped_cases]
+
+
+# ---------------------------------------------------------------------------
+# Parser
+# ---------------------------------------------------------------------------
+
+def parse_suite_xml(xml_path: Path) -> SuiteResult:
+    tree = ET.parse(xml_path)
+    root = tree.getroot()
+
+    # Handle both <testsuite> root and <testsuites> wrapper
+    suites = [root] if root.tag == "testsuite" else root.findall("testsuite")
+
+    # Merge multiple suites from one file into a single SuiteResult
+    total = failures = errors = skipped = 0
+    elapsed = 0.0
+    name = xml_path.stem
+    cases: list[TestCase] = []
+
+    for suite in suites:
+        total    += int(suite.get("tests",    0))
+        failures += int(suite.get("failures", 0))
+        errors   += int(suite.get("errors",   0))
+        skipped  += int(suite.get("skipped",  0))
+        elapsed  += float(suite.get("time",   0.0))
+        if suite.get("name"):
+            name = suite.get("name")
+
+        for tc in suite.findall("testcase"):
+            fail_el = tc.find("failure")
+            err_el  = tc.find("error")
+            skip_el = tc.find("skipped")
+            cases.append(TestCase(
+                classname=tc.get("classname", ""),
+                name=tc.get("name", ""),
+                time=float(tc.get("time", 0.0)),
+                failure=fail_el.get("message", fail_el.text or "") if fail_el is not None else None,
+                error=err_el.get("message",  err_el.text  or "") if err_el  is not None else None,
+                skipped=skip_el is not None,
+            ))
+
+    return SuiteResult(
+        name=name, total=total, failures=failures,
+        errors=errors, skipped=skipped, time=elapsed, cases=cases,
+    )
+
+
+def load_module(module_dir: Path, results_subdir: str) -> Optional[ModuleResult]:
+    results_dir = module_dir / results_subdir
+    if not results_dir.is_dir():
+        return None
+
+    xml_files = sorted(results_dir.glob("*.xml"))
+    if not xml_files:
+        return None
+
+    mod = ModuleResult(name=module_dir.name)
+    for xml_path in xml_files:
+        try:
+            mod.suites.append(parse_suite_xml(xml_path))
+        except ET.ParseError:
+            pass  # skip malformed files silently
+    return mod if mod.suites else None
+
+
+# ---------------------------------------------------------------------------
+# Formatter
+# ---------------------------------------------------------------------------
+
+def _truncate(text: str, max_len: int = 120) -> str:
+    text = " ".join(text.split())        # collapse whitespace
+    return text[:max_len] + "…" if len(text) > max_len else text
+
+
+def format_module(mod: ModuleResult) -> str:
+    parts = [f"[{mod.name}]"]
+
+    if mod.is_clean and mod.skipped == 0:
+        parts.append(f"tests: {mod.total} ✅")
+        return " ".join(parts)
+
+    parts.append(f"tests: {mod.total}")
+    if mod.failures:  parts.append(f"failed: {mod.failures}")
+    if mod.errors:    parts.append(f"errors: {mod.errors}")
+    if mod.skipped:   parts.append(f"skipped: {mod.skipped}")
+
+    # Agent hint only when there are actual failures/errors
+    if not mod.is_clean:
+        parts.append(f" # hint: run ./test {mod.name} for details")
+
+    lines = [" ".join(parts)]
+
+    # List each failed/errored test — this IS the actionable info
+    for tc in mod.bad_cases:
+        msg = tc.failure if tc.failure is not None else tc.error
+        label = f"  {tc.status}: {tc.short_class} > {tc.name}"
+        if msg:
+            label += f"  [{_truncate(msg, 80)}]"
+        lines.append(label)
+
+    # Skipped: compact, one line total
+    if mod.skipped_cases:
+        skipped_names = ", ".join(
+            f"{c.short_class}.{c.name}" for c in mod.skipped_cases[:5]
+        )
+        if len(mod.skipped_cases) > 5:
+            skipped_names += f" (+{len(mod.skipped_cases) - 5} more)"
+        lines.append(f"  SKIP: {skipped_names}")
+
+    return "\n".join(lines)
+
+
+# ---------------------------------------------------------------------------
+# Runner
+# ---------------------------------------------------------------------------
+
+def run(modules_dir: str, results_subdir: str, module_filter: Optional[str]) -> None:
+    base = Path(modules_dir)
+    if not base.is_dir():
+        print(f"ERROR: modules directory not found: {base}", file=sys.stderr)
+        sys.exit(1)
+
+    # Resolve which module dirs to scan
+    if module_filter and module_filter != "all":
+        mod_dir = base / module_filter
+        if not mod_dir.is_dir():
+            print(f"ERROR: module not found: {mod_dir}", file=sys.stderr)
+            sys.exit(1)
+        candidates = [mod_dir]
+    else:
+        candidates = sorted(p for p in base.iterdir() if p.is_dir())
+
+    results: list[str] = []
+    missing: list[str] = []
+
+    for mod_dir in candidates:
+        if mod_dir.name.startswith("build"):
+            continue
+        mod = load_module(mod_dir, results_subdir)
+        if mod is None:
+            missing.append(mod_dir.name)
+            continue
+        results.append(format_module(mod))
+
+    print("\n".join(results))
+
+    if missing:
+        print(
+            f"\n# Modules without test results: {', '.join(missing)}",
+            file=sys.stderr,
+        )
+
+
+# ---------------------------------------------------------------------------
+# Entry point
+# ---------------------------------------------------------------------------
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Minimal test-gap reporter for JUnit XML results across modules."
+    )
+    parser.add_argument(
+        "--module", "-m",
+        nargs="?",
+        const="all",
+        default="all",
+        help="Module name to scan, or 'all' (default: all)",
+    )
+    parser.add_argument(
+        "--modules-dir",
+        default="./modules",
+        help="Root directory containing one sub-directory per module (default: ./modules)",
+    )
+    parser.add_argument(
+        "--results-subdir",
+        default="build/test-results/test",
+        help="Sub-path inside each module dir where *.xml files live (default: build/test-results/test)",
+    )
+    args = parser.parse_args()
+
+    filter_ = None if args.module == "all" else args.module
+    run(args.modules_dir, args.results_subdir, filter_)
+
+
+if __name__ == "__main__":
+    main()

modules/api/CHANGELOG.md

@@ -4,3 +4,26 @@
 ##  (2026-03-29)
 ##  (2026-03-31)
 ##  (2026-04-01)
+##  (2026-04-01)
+##  (2026-04-01)
+##  (2026-04-02)
+
+### Features
+
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+##  (2026-04-03)
+
+### Features
+
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+##  (2026-04-07)
+
+### Features
+
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+##  (2026-04-12)
+
+### Features
+
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+* NCS-25 Add linters to keep quality up ([#27](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/27)) ([fd4e67d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fd4e67d4f782a7e955822d90cb909d0a81676fb2))

modules/api/build.gradle.kts

@@ -59,7 +59,7 @@ tasks.test {
     useJUnitPlatform {
         includeEngines("scalatest")
         testLogging {
-            events("passed", "skipped", "failed")
+            events("skipped", "failed")
         }
     }
     finalizedBy(tasks.reportScoverage)

modules/api/src/main/scala/de/nowchess/api/board/Board.scala

@@ -7,19 +7,28 @@ object Board:
   def apply(pieces: Map[Square, Piece]): Board = pieces
 
   extension (b: Board)
-    def pieceAt(sq: Square): Option[Piece] = b.get(sq)
+    def pieceAt(sq: Square): Option[Piece]       = b.get(sq)
     def updated(sq: Square, piece: Piece): Board = b.updated(sq, piece)
-    def removed(sq: Square): Board = b.removed(sq)
+    def removed(sq: Square): Board               = b.removed(sq)
     def withMove(from: Square, to: Square): (Board, Option[Piece]) =
-      val captured = b.get(to)
+      val captured     = b.get(to)
       val updatedBoard = b.removed(from).updated(to, b(from))
       (updatedBoard, captured)
+    def applyMove(move: de.nowchess.api.move.Move): Board =
+      val (updatedBoard, _) = b.withMove(move.from, move.to)
+      updatedBoard
     def pieces: Map[Square, Piece] = b
 
   val initial: Board =
     val backRank: Vector[PieceType] = Vector(
-      PieceType.Rook, PieceType.Knight, PieceType.Bishop, PieceType.Queen,
-      PieceType.King, PieceType.Bishop, PieceType.Knight, PieceType.Rook
+      PieceType.Rook,
+      PieceType.Knight,
+      PieceType.Bishop,
+      PieceType.Queen,
+      PieceType.King,
+      PieceType.Bishop,
+      PieceType.Knight,
+      PieceType.Rook,
     )
     val entries = for
       fileIdx <- 0 until 8
@@ -27,7 +36,7 @@ object Board:
         (Color.White, Rank.R1, backRank(fileIdx)),
         (Color.White, Rank.R2, PieceType.Pawn),
         (Color.Black, Rank.R8, backRank(fileIdx)),
-        (Color.Black, Rank.R7, PieceType.Pawn)
+        (Color.Black, Rank.R7, PieceType.Pawn),
       )
     yield Square(File.values(fileIdx), rank) -> Piece(color, pieceType)
     Board(entries.toMap)

modules/api/src/main/scala/de/nowchess/api/board/CastlingRights.scala

@@ -0,0 +1,68 @@
+package de.nowchess.api.board
+
+/** Unified castling rights tracker for all four sides. Tracks whether castling is still available for each side and
+  * direction.
+  *
+  * @param whiteKingSide
+  *   White's king-side castling (0-0) still legally available
+  * @param whiteQueenSide
+  *   White's queen-side castling (0-0-0) still legally available
+  * @param blackKingSide
+  *   Black's king-side castling (0-0) still legally available
+  * @param blackQueenSide
+  *   Black's queen-side castling (0-0-0) still legally available
+  */
+final case class CastlingRights(
+    whiteKingSide: Boolean,
+    whiteQueenSide: Boolean,
+    blackKingSide: Boolean,
+    blackQueenSide: Boolean,
+):
+  /** Check if either side has any castling rights remaining.
+    */
+  def hasAnyRights: Boolean =
+    whiteKingSide || whiteQueenSide || blackKingSide || blackQueenSide
+
+  /** Check if a specific color has any castling rights remaining.
+    */
+  def hasRights(color: Color): Boolean = color match
+    case Color.White => whiteKingSide || whiteQueenSide
+    case Color.Black => blackKingSide || blackQueenSide
+
+  /** Revoke all castling rights for a specific color.
+    */
+  def revokeColor(color: Color): CastlingRights = color match
+    case Color.White => copy(whiteKingSide = false, whiteQueenSide = false)
+    case Color.Black => copy(blackKingSide = false, blackQueenSide = false)
+
+  /** Revoke a specific castling right.
+    */
+  def revokeKingSide(color: Color): CastlingRights = color match
+    case Color.White => copy(whiteKingSide = false)
+    case Color.Black => copy(blackKingSide = false)
+
+  /** Revoke a specific castling right.
+    */
+  def revokeQueenSide(color: Color): CastlingRights = color match
+    case Color.White => copy(whiteQueenSide = false)
+    case Color.Black => copy(blackQueenSide = false)
+
+object CastlingRights:
+  /** No castling rights for any side. */
+  val None: CastlingRights = CastlingRights(
+    whiteKingSide = false,
+    whiteQueenSide = false,
+    blackKingSide = false,
+    blackQueenSide = false,
+  )
+
+  /** All castling rights available. */
+  val All: CastlingRights = CastlingRights(
+    whiteKingSide = true,
+    whiteQueenSide = true,
+    blackKingSide = true,
+    blackQueenSide = true,
+  )
+
+  /** Standard starting position castling rights (both sides can castle both ways). */
+  val Initial: CastlingRights = All

modules/api/src/main/scala/de/nowchess/api/board/Piece.scala

@@ -5,16 +5,16 @@ final case class Piece(color: Color, pieceType: PieceType)
 
 object Piece:
   // Convenience constructors
-  val WhitePawn:   Piece = Piece(Color.White, PieceType.Pawn)
+  val WhitePawn: Piece   = Piece(Color.White, PieceType.Pawn)
   val WhiteKnight: Piece = Piece(Color.White, PieceType.Knight)
   val WhiteBishop: Piece = Piece(Color.White, PieceType.Bishop)
-  val WhiteRook:   Piece = Piece(Color.White, PieceType.Rook)
-  val WhiteQueen:  Piece = Piece(Color.White, PieceType.Queen)
-  val WhiteKing:   Piece = Piece(Color.White, PieceType.King)
+  val WhiteRook: Piece   = Piece(Color.White, PieceType.Rook)
+  val WhiteQueen: Piece  = Piece(Color.White, PieceType.Queen)
+  val WhiteKing: Piece   = Piece(Color.White, PieceType.King)
 
-  val BlackPawn:   Piece = Piece(Color.Black, PieceType.Pawn)
+  val BlackPawn: Piece   = Piece(Color.Black, PieceType.Pawn)
   val BlackKnight: Piece = Piece(Color.Black, PieceType.Knight)
   val BlackBishop: Piece = Piece(Color.Black, PieceType.Bishop)
-  val BlackRook:   Piece = Piece(Color.Black, PieceType.Rook)
-  val BlackQueen:  Piece = Piece(Color.Black, PieceType.Queen)
-  val BlackKing:   Piece = Piece(Color.Black, PieceType.King)
+  val BlackRook: Piece   = Piece(Color.Black, PieceType.Rook)
+  val BlackQueen: Piece  = Piece(Color.Black, PieceType.Queen)
+  val BlackKing: Piece   = Piece(Color.Black, PieceType.King)

modules/api/src/main/scala/de/nowchess/api/board/Square.scala

@@ -1,41 +1,53 @@
 package de.nowchess.api.board
 
-/**
- * A file (column) on the chess board, a–h.
- * Ordinal values 0–7 correspond to a–h.
- */
+/** A file (column) on the chess board, a–h. Ordinal values 0–7 correspond to a–h.
+  */
 enum File:
   case A, B, C, D, E, F, G, H
 
-/**
- * A rank (row) on the chess board, 1–8.
- * Ordinal values 0–7 correspond to ranks 1–8.
- */
+/** A rank (row) on the chess board, 1–8. Ordinal values 0–7 correspond to ranks 1–8.
+  */
 enum Rank:
   case R1, R2, R3, R4, R5, R6, R7, R8
 
-/**
- * A unique square on the board, identified by its file and rank.
- *
- * @param file the column, a–h
- * @param rank the row, 1–8
- */
+/** A unique square on the board, identified by its file and rank.
+  *
+  * @param file
+  *   the column, a–h
+  * @param rank
+  *   the row, 1–8
+  */
 final case class Square(file: File, rank: Rank):
   /** Algebraic notation string, e.g. "e4". */
   override def toString: String =
     s"${file.toString.toLowerCase}${rank.ordinal + 1}"
 
 object Square:
-  /** Parse a square from algebraic notation (e.g. "e4").
-   *  Returns None if the input is not a valid square name. */
+  /** Parse a square from algebraic notation (e.g. "e4"). Returns None if the input is not a valid square name.
+    */
   def fromAlgebraic(s: String): Option[Square] =
     if s.length != 2 then None
     else
       val fileChar = s.charAt(0)
       val rankChar = s.charAt(1)
-      val fileOpt = File.values.find(_.toString.equalsIgnoreCase(fileChar.toString))
+      val fileOpt  = File.values.find(_.toString.equalsIgnoreCase(fileChar.toString))
       val rankOpt =
-        rankChar.toString.toIntOption.flatMap(n =>
-          if n >= 1 && n <= 8 then Some(Rank.values(n - 1)) else None
-        )
+        rankChar.toString.toIntOption.flatMap(n => if n >= 1 && n <= 8 then Some(Rank.values(n - 1)) else None)
       for f <- fileOpt; r <- rankOpt yield Square(f, r)
+
+  val all: IndexedSeq[Square] =
+    for
+      r <- Rank.values.toIndexedSeq
+      f <- File.values.toIndexedSeq
+    yield Square(f, r)
+
+  /** Compute a target square by offsetting file and rank. Returns None if the resulting square is outside the board
+    * (0-7 range).
+    */
+  extension (sq: Square)
+    def offset(fileDelta: Int, rankDelta: Int): Option[Square] =
+      val newFileOrd = sq.file.ordinal + fileDelta
+      val newRankOrd = sq.rank.ordinal + rankDelta
+      if newFileOrd >= 0 && newFileOrd < 8 && newRankOrd >= 0 && newRankOrd < 8 then
+        Some(Square(File.values(newFileOrd), Rank.values(newRankOrd)))
+      else None

modules/api/src/main/scala/de/nowchess/api/game/DrawReason.scala

@@ -0,0 +1,8 @@
+package de.nowchess.api.game
+
+/** Reason why a game ended in a draw. */
+enum DrawReason:
+  case Stalemate
+  case InsufficientMaterial
+  case FiftyMoveRule
+  case Agreement

modules/api/src/main/scala/de/nowchess/api/game/GameContext.scala

@@ -0,0 +1,47 @@
+package de.nowchess.api.game
+
+import de.nowchess.api.board.{Board, CastlingRights, Color, Square}
+import de.nowchess.api.move.Move
+
+/** Immutable bundle of complete game state. All state changes produce new GameContext instances.
+  */
+case class GameContext(
+    board: Board,
+    turn: Color,
+    castlingRights: CastlingRights,
+    enPassantSquare: Option[Square],
+    halfMoveClock: Int,
+    moves: List[Move],
+    result: Option[GameResult] = None,
+):
+  /** Create new context with updated board. */
+  def withBoard(newBoard: Board): GameContext = copy(board = newBoard)
+
+  /** Create new context with updated turn. */
+  def withTurn(newTurn: Color): GameContext = copy(turn = newTurn)
+
+  /** Create new context with updated castling rights. */
+  def withCastlingRights(newRights: CastlingRights): GameContext = copy(castlingRights = newRights)
+
+  /** Create new context with updated en passant square. */
+  def withEnPassantSquare(newSq: Option[Square]): GameContext = copy(enPassantSquare = newSq)
+
+  /** Create new context with updated half-move clock. */
+  def withHalfMoveClock(newClock: Int): GameContext = copy(halfMoveClock = newClock)
+
+  /** Create new context with move appended to history. */
+  def withMove(move: Move): GameContext = copy(moves = moves :+ move)
+
+  /** Create new context with updated result. */
+  def withResult(newResult: Option[GameResult]): GameContext = copy(result = newResult)
+
+object GameContext:
+  /** Initial position: white to move, all castling rights, no en passant. */
+  def initial: GameContext = GameContext(
+    board = Board.initial,
+    turn = Color.White,
+    castlingRights = CastlingRights.Initial,
+    enPassantSquare = None,
+    halfMoveClock = 0,
+    moves = List.empty,
+  )

modules/api/src/main/scala/de/nowchess/api/game/GameResult.scala

@@ -0,0 +1,8 @@
+package de.nowchess.api.game
+
+import de.nowchess.api.board.Color
+
+/** Outcome of a finished game. */
+enum GameResult:
+  case Win(color: Color)
+  case Draw(reason: DrawReason)

modules/api/src/main/scala/de/nowchess/api/game/GameState.scala

@@ -1,67 +0,0 @@
-package de.nowchess.api.game
-
-import de.nowchess.api.board.{Color, Square}
-
-/**
- * Castling availability flags for one side.
- *
- * @param kingSide  king-side castling still legally available
- * @param queenSide queen-side castling still legally available
- */
-final case class CastlingRights(kingSide: Boolean, queenSide: Boolean)
-
-object CastlingRights:
-  val None: CastlingRights = CastlingRights(kingSide = false, queenSide = false)
-  val Both: CastlingRights = CastlingRights(kingSide = true, queenSide = true)
-
-/** Outcome of a finished game. */
-enum GameResult:
-  case WhiteWins
-  case BlackWins
-  case Draw
-
-/** Lifecycle state of a game. */
-enum GameStatus:
-  case NotStarted
-  case InProgress
-  case Finished(result: GameResult)
-
-/**
- * A FEN-compatible snapshot of board and game state.
- *
- * The board is represented as a FEN piece-placement string (rank 8 to rank 1,
- * separated by '/').  All other fields mirror standard FEN fields.
- *
- * @param piecePlacement  FEN piece-placement field, e.g.
- *                        "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR"
- * @param activeColor     side to move
- * @param castlingWhite   castling rights for White
- * @param castlingBlack   castling rights for Black
- * @param enPassantTarget square behind the double-pushed pawn, if any
- * @param halfMoveClock   plies since last capture or pawn advance (50-move rule)
- * @param fullMoveNumber  increments after Black's move, starts at 1
- * @param status          current lifecycle status of the game
- */
-final case class GameState(
-  piecePlacement: String,
-  activeColor: Color,
-  castlingWhite: CastlingRights,
-  castlingBlack: CastlingRights,
-  enPassantTarget: Option[Square],
-  halfMoveClock: Int,
-  fullMoveNumber: Int,
-  status: GameStatus
-)
-
-object GameState:
-  /** Standard starting position. */
-  val initial: GameState = GameState(
-    piecePlacement  = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR",
-    activeColor     = Color.White,
-    castlingWhite   = CastlingRights.Both,
-    castlingBlack   = CastlingRights.Both,
-    enPassantTarget = None,
-    halfMoveClock   = 0,
-    fullMoveNumber  = 1,
-    status          = GameStatus.InProgress
-  )

modules/api/src/main/scala/de/nowchess/api/move/Move.scala

@@ -9,25 +9,31 @@ enum PromotionPiece:
 /** Classifies special move semantics beyond a plain quiet move or capture. */
 enum MoveType:
   /** A normal move or capture with no special rule. */
-  case Normal
+  case Normal(isCapture: Boolean = false)
+
   /** Kingside castling (O-O). */
   case CastleKingside
+
   /** Queenside castling (O-O-O). */
   case CastleQueenside
+
   /** En-passant pawn capture. */
   case EnPassant
+
   /** Pawn promotion; carries the chosen promotion piece. */
   case Promotion(piece: PromotionPiece)
 
-/**
- * A half-move (ply) in a chess game.
- *
- * @param from     origin square
- * @param to       destination square
- * @param moveType special semantics; defaults to Normal
- */
+/** A half-move (ply) in a chess game.
+  *
+  * @param from
+  *   origin square
+  * @param to
+  *   destination square
+  * @param moveType
+  *   special semantics; defaults to Normal
+  */
 final case class Move(
-  from: Square,
-  to: Square,
-  moveType: MoveType = MoveType.Normal
+    from: Square,
+    to: Square,
+    moveType: MoveType = MoveType.Normal(),
 )

modules/api/src/main/scala/de/nowchess/api/player/PlayerInfo.scala

@@ -1,27 +1,26 @@
 package de.nowchess.api.player
 
-/**
- * An opaque player identifier.
- *
- * Wraps a plain String so that IDs are not accidentally interchanged with
- * other String values at compile time.
- */
+/** An opaque player identifier.
+  *
+  * Wraps a plain String so that IDs are not accidentally interchanged with other String values at compile time.
+  */
 opaque type PlayerId = String
 
 object PlayerId:
-  def apply(value: String): PlayerId = value
+  def apply(value: String): PlayerId         = value
   extension (id: PlayerId) def value: String = id
 
-/**
- * The minimal cross-service identity stub for a player.
- *
- * Full profile data (email, rating history, etc.) lives in the user-management
- * service.  Only what every service needs is held here.
- *
- * @param id          unique identifier
- * @param displayName human-readable name shown in the UI
- */
+/** The minimal cross-service identity stub for a player.
+  *
+  * Full profile data (email, rating history, etc.) lives in the user-management service. Only what every service needs
+  * is held here.
+  *
+  * @param id
+  *   unique identifier
+  * @param displayName
+  *   human-readable name shown in the UI
+  */
 final case class PlayerInfo(
-  id: PlayerId,
-  displayName: String
+    id: PlayerId,
+    displayName: String,
 )

modules/api/src/main/scala/de/nowchess/api/response/ApiResponse.scala

@@ -1,13 +1,12 @@
 package de.nowchess.api.response
 
-/**
- * A standardised envelope for every API response.
- *
- * Success and failure are modelled as subtypes so that callers
- * can pattern-match exhaustively.
- *
- * @tparam A the payload type for a successful response
- */
+/** A standardised envelope for every API response.
+  *
+  * Success and failure are modelled as subtypes so that callers can pattern-match exhaustively.
+  *
+  * @tparam A
+  *   the payload type for a successful response
+  */
 sealed trait ApiResponse[+A]
 
 object ApiResponse:
@@ -20,43 +19,49 @@ object ApiResponse:
   /** Convenience constructor for a single-error failure. */
   def error(err: ApiError): Failure = Failure(List(err))
 
-/**
- * A structured error descriptor.
- *
- * @param code    machine-readable error code (e.g. "INVALID_MOVE", "NOT_FOUND")
- * @param message human-readable explanation
- * @param field   optional field name when the error relates to a specific input
- */
+/** A structured error descriptor.
+  *
+  * @param code
+  *   machine-readable error code (e.g. "INVALID_MOVE", "NOT_FOUND")
+  * @param message
+  *   human-readable explanation
+  * @param field
+  *   optional field name when the error relates to a specific input
+  */
 final case class ApiError(
-  code: String,
-  message: String,
-  field: Option[String] = None
+    code: String,
+    message: String,
+    field: Option[String] = None,
 )
 
-/**
- * Pagination metadata for list responses.
- *
- * @param page       current 0-based page index
- * @param pageSize   number of items per page
- * @param totalItems total number of items across all pages
- */
+/** Pagination metadata for list responses.
+  *
+  * @param page
+  *   current 0-based page index
+  * @param pageSize
+  *   number of items per page
+  * @param totalItems
+  *   total number of items across all pages
+  */
 final case class Pagination(
-  page: Int,
-  pageSize: Int,
-  totalItems: Long
+    page: Int,
+    pageSize: Int,
+    totalItems: Long,
 ):
   def totalPages: Int =
     if pageSize <= 0 then 0
     else Math.ceil(totalItems.toDouble / pageSize).toInt
 
-/**
- * A paginated list response envelope.
- *
- * @param items      the items on the current page
- * @param pagination pagination metadata
- * @tparam A         the item type
- */
+/** A paginated list response envelope.
+  *
+  * @param items
+  *   the items on the current page
+  * @param pagination
+  *   pagination metadata
+  * @tparam A
+  *   the item type
+  */
 final case class PagedResponse[A](
-  items: List[A],
-  pagination: Pagination
+    items: List[A],
+    pagination: Pagination,
 )

modules/api/src/test/scala/de/nowchess/api/board/BoardTest.scala

@@ -1,5 +1,6 @@
 package de.nowchess.api.board
 
+import de.nowchess.api.move.Move
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
 
@@ -7,13 +8,9 @@ class BoardTest extends AnyFunSuite with Matchers:
 
   private val e2 = Square(File.E, Rank.R2)
   private val e4 = Square(File.E, Rank.R4)
-  private val d7 = Square(File.D, Rank.R7)
 
-  test("pieceAt returns Some for occupied square") {
+  test("pieceAt resolves occupied and empty squares") {
     Board.initial.pieceAt(e2) shouldBe Some(Piece.WhitePawn)
-  }
-
-  test("pieceAt returns None for empty square") {
     Board.initial.pieceAt(e4) shouldBe None
   }
 
@@ -25,55 +22,43 @@ class BoardTest extends AnyFunSuite with Matchers:
   }
 
   test("withMove returns captured piece when destination is occupied") {
-    val from = Square(File.A, Rank.R1)
-    val to   = Square(File.A, Rank.R8)
-    val b    = Board(Map(from -> Piece.WhiteRook, to -> Piece.BlackRook))
+    val from              = Square(File.A, Rank.R1)
+    val to                = Square(File.A, Rank.R8)
+    val b                 = Board(Map(from -> Piece.WhiteRook, to -> Piece.BlackRook))
     val (board, captured) = b.withMove(from, to)
     captured shouldBe Some(Piece.BlackRook)
     board.pieceAt(to) shouldBe Some(Piece.WhiteRook)
     board.pieceAt(from) shouldBe None
   }
 
-  test("pieces returns the underlying map") {
-    val map = Map(e2 -> Piece.WhitePawn)
-    val b   = Board(map)
-    b.pieces shouldBe map
-  }
-
-  test("Board.apply constructs board from map") {
+  test("Board.apply and pieces expose the wrapped map") {
     val map = Map(e2 -> Piece.WhitePawn)
     val b   = Board(map)
     b.pieceAt(e2) shouldBe Some(Piece.WhitePawn)
+    b.pieces shouldBe map
   }
 
-  test("initial board has 32 pieces") {
+  test("initial board has expected material and pawn placement") {
     Board.initial.pieces should have size 32
-  }
-
-  test("initial board has 16 white pieces") {
     Board.initial.pieces.values.count(_.color == Color.White) shouldBe 16
-  }
-
-  test("initial board has 16 black pieces") {
     Board.initial.pieces.values.count(_.color == Color.Black) shouldBe 16
-  }
 
-  test("initial board white pawns on rank 2") {
     File.values.foreach { file =>
       Board.initial.pieceAt(Square(file, Rank.R2)) shouldBe Some(Piece.WhitePawn)
-    }
-  }
-
-  test("initial board black pawns on rank 7") {
-    File.values.foreach { file =>
       Board.initial.pieceAt(Square(file, Rank.R7)) shouldBe Some(Piece.BlackPawn)
     }
   }
 
   test("initial board white back rank") {
     val expectedBackRank = Vector(
-      PieceType.Rook, PieceType.Knight, PieceType.Bishop, PieceType.Queen,
-      PieceType.King, PieceType.Bishop, PieceType.Knight, PieceType.Rook
+      PieceType.Rook,
+      PieceType.Knight,
+      PieceType.Bishop,
+      PieceType.Queen,
+      PieceType.King,
+      PieceType.Bishop,
+      PieceType.Knight,
+      PieceType.Rook,
     )
     File.values.zipWithIndex.foreach { (file, i) =>
       Board.initial.pieceAt(Square(file, Rank.R1)) shouldBe
@@ -83,8 +68,14 @@ class BoardTest extends AnyFunSuite with Matchers:
 
   test("initial board black back rank") {
     val expectedBackRank = Vector(
-      PieceType.Rook, PieceType.Knight, PieceType.Bishop, PieceType.Queen,
-      PieceType.King, PieceType.Bishop, PieceType.Knight, PieceType.Rook
+      PieceType.Rook,
+      PieceType.Knight,
+      PieceType.Bishop,
+      PieceType.Queen,
+      PieceType.King,
+      PieceType.Bishop,
+      PieceType.Knight,
+      PieceType.Rook,
     )
     File.values.zipWithIndex.foreach { (file, i) =>
       Board.initial.pieceAt(Square(file, Rank.R8)) shouldBe
@@ -97,26 +88,31 @@ class BoardTest extends AnyFunSuite with Matchers:
     for
       rank <- emptyRanks
       file <- File.values
-    do
-      Board.initial.pieceAt(Square(file, rank)) shouldBe None
+    do Board.initial.pieceAt(Square(file, rank)) shouldBe None
   }
 
-  test("updated adds or replaces piece at square") {
-    val b = Board(Map(e2 -> Piece.WhitePawn))
-    val updated = b.updated(e4, Piece.WhiteKnight)
-    updated.pieceAt(e2) shouldBe Some(Piece.WhitePawn)
-    updated.pieceAt(e4) shouldBe Some(Piece.WhiteKnight)
-  }
+  test("updated adds and replaces piece at squares") {
+    val b     = Board(Map(e2 -> Piece.WhitePawn))
+    val added = b.updated(e4, Piece.WhiteKnight)
+    added.pieceAt(e2) shouldBe Some(Piece.WhitePawn)
+    added.pieceAt(e4) shouldBe Some(Piece.WhiteKnight)
 
-  test("updated replaces existing piece") {
-    val b = Board(Map(e2 -> Piece.WhitePawn))
-    val updated = b.updated(e2, Piece.WhiteKnight)
-    updated.pieceAt(e2) shouldBe Some(Piece.WhiteKnight)
+    val replaced = b.updated(e2, Piece.WhiteKnight)
+    replaced.pieceAt(e2) shouldBe Some(Piece.WhiteKnight)
   }
 
   test("removed deletes piece from board") {
-    val b = Board(Map(e2 -> Piece.WhitePawn, e4 -> Piece.WhiteKnight))
+    val b       = Board(Map(e2 -> Piece.WhitePawn, e4 -> Piece.WhiteKnight))
     val removed = b.removed(e2)
     removed.pieceAt(e2) shouldBe None
     removed.pieceAt(e4) shouldBe Some(Piece.WhiteKnight)
   }
+
+  test("applyMove uses move.from and move.to to relocate a piece") {
+    val b = Board(Map(e2 -> Piece.WhitePawn))
+
+    val moved = b.applyMove(Move(e2, e4))
+
+    moved.pieceAt(e4) shouldBe Some(Piece.WhitePawn)
+    moved.pieceAt(e2) shouldBe None
+  }

modules/api/src/test/scala/de/nowchess/api/board/CastlingRightsTest.scala

@@ -0,0 +1,56 @@
+package de.nowchess.api.board
+
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+
+class CastlingRightsTest extends AnyFunSuite with Matchers:
+
+  test("hasAnyRights and hasRights reflect current flags"):
+    val rights = CastlingRights(
+      whiteKingSide = true,
+      whiteQueenSide = false,
+      blackKingSide = false,
+      blackQueenSide = true,
+    )
+
+    rights.hasAnyRights shouldBe true
+    rights.hasRights(Color.White) shouldBe true
+    rights.hasRights(Color.Black) shouldBe true
+
+    CastlingRights.None.hasAnyRights shouldBe false
+    CastlingRights.None.hasRights(Color.White) shouldBe false
+    CastlingRights.None.hasRights(Color.Black) shouldBe false
+
+  test("revokeColor clears both castling sides for selected color"):
+    val all = CastlingRights.All
+
+    val whiteRevoked = all.revokeColor(Color.White)
+    whiteRevoked.whiteKingSide shouldBe false
+    whiteRevoked.whiteQueenSide shouldBe false
+    whiteRevoked.blackKingSide shouldBe true
+    whiteRevoked.blackQueenSide shouldBe true
+
+    val blackRevoked = all.revokeColor(Color.Black)
+    blackRevoked.whiteKingSide shouldBe true
+    blackRevoked.whiteQueenSide shouldBe true
+    blackRevoked.blackKingSide shouldBe false
+    blackRevoked.blackQueenSide shouldBe false
+
+  test("revokeKingSide and revokeQueenSide disable only requested side"):
+    val all = CastlingRights.All
+
+    val whiteKingSideRevoked = all.revokeKingSide(Color.White)
+    whiteKingSideRevoked.whiteKingSide shouldBe false
+    whiteKingSideRevoked.whiteQueenSide shouldBe true
+
+    val whiteQueenSideRevoked = all.revokeQueenSide(Color.White)
+    whiteQueenSideRevoked.whiteKingSide shouldBe true
+    whiteQueenSideRevoked.whiteQueenSide shouldBe false
+
+    val blackKingSideRevoked = all.revokeKingSide(Color.Black)
+    blackKingSideRevoked.blackKingSide shouldBe false
+    blackKingSideRevoked.blackQueenSide shouldBe true
+
+    val blackQueenSideRevoked = all.revokeQueenSide(Color.Black)
+    blackQueenSideRevoked.blackKingSide shouldBe true
+    blackQueenSideRevoked.blackQueenSide shouldBe false

modules/api/src/test/scala/de/nowchess/api/board/ColorTest.scala

@@ -5,18 +5,13 @@ import org.scalatest.matchers.should.Matchers
 
 class ColorTest extends AnyFunSuite with Matchers:
 
-  test("White.opposite returns Black") {
-    Color.White.opposite shouldBe Color.Black
-  }
+  test("Color values expose opposite and label consistently"):
+    val cases = List(
+      (Color.White, Color.Black, "White"),
+      (Color.Black, Color.White, "Black"),
+    )
 
-  test("Black.opposite returns White") {
-    Color.Black.opposite shouldBe Color.White
-  }
-
-  test("White.label returns 'White'") {
-    Color.White.label shouldBe "White"
-  }
-
-  test("Black.label returns 'Black'") {
-    Color.Black.label shouldBe "Black"
-  }
+    cases.foreach { (color, opposite, label) =>
+      color.opposite shouldBe opposite
+      color.label shouldBe label
+    }

modules/api/src/test/scala/de/nowchess/api/board/PieceTest.scala

@@ -7,54 +7,27 @@ class PieceTest extends AnyFunSuite with Matchers:
 
   test("Piece holds color and pieceType") {
     val p = Piece(Color.White, PieceType.Queen)
-    p.color    shouldBe Color.White
+    p.color shouldBe Color.White
     p.pieceType shouldBe PieceType.Queen
   }
 
-  test("WhitePawn convenience constant") {
-    Piece.WhitePawn shouldBe Piece(Color.White, PieceType.Pawn)
-  }
+  test("all convenience constants map to expected color and piece type") {
+    val expected = List(
+      Piece.WhitePawn   -> Piece(Color.White, PieceType.Pawn),
+      Piece.WhiteKnight -> Piece(Color.White, PieceType.Knight),
+      Piece.WhiteBishop -> Piece(Color.White, PieceType.Bishop),
+      Piece.WhiteRook   -> Piece(Color.White, PieceType.Rook),
+      Piece.WhiteQueen  -> Piece(Color.White, PieceType.Queen),
+      Piece.WhiteKing   -> Piece(Color.White, PieceType.King),
+      Piece.BlackPawn   -> Piece(Color.Black, PieceType.Pawn),
+      Piece.BlackKnight -> Piece(Color.Black, PieceType.Knight),
+      Piece.BlackBishop -> Piece(Color.Black, PieceType.Bishop),
+      Piece.BlackRook   -> Piece(Color.Black, PieceType.Rook),
+      Piece.BlackQueen  -> Piece(Color.Black, PieceType.Queen),
+      Piece.BlackKing   -> Piece(Color.Black, PieceType.King),
+    )
 
-  test("WhiteKnight convenience constant") {
-    Piece.WhiteKnight shouldBe Piece(Color.White, PieceType.Knight)
-  }
-
-  test("WhiteBishop convenience constant") {
-    Piece.WhiteBishop shouldBe Piece(Color.White, PieceType.Bishop)
-  }
-
-  test("WhiteRook convenience constant") {
-    Piece.WhiteRook shouldBe Piece(Color.White, PieceType.Rook)
-  }
-
-  test("WhiteQueen convenience constant") {
-    Piece.WhiteQueen shouldBe Piece(Color.White, PieceType.Queen)
-  }
-
-  test("WhiteKing convenience constant") {
-    Piece.WhiteKing shouldBe Piece(Color.White, PieceType.King)
-  }
-
-  test("BlackPawn convenience constant") {
-    Piece.BlackPawn shouldBe Piece(Color.Black, PieceType.Pawn)
-  }
-
-  test("BlackKnight convenience constant") {
-    Piece.BlackKnight shouldBe Piece(Color.Black, PieceType.Knight)
-  }
-
-  test("BlackBishop convenience constant") {
-    Piece.BlackBishop shouldBe Piece(Color.Black, PieceType.Bishop)
-  }
-
-  test("BlackRook convenience constant") {
-    Piece.BlackRook shouldBe Piece(Color.Black, PieceType.Rook)
-  }
-
-  test("BlackQueen convenience constant") {
-    Piece.BlackQueen shouldBe Piece(Color.Black, PieceType.Queen)
-  }
-
-  test("BlackKing convenience constant") {
-    Piece.BlackKing shouldBe Piece(Color.Black, PieceType.King)
+    expected.foreach { case (actual, wanted) =>
+      actual shouldBe wanted
+    }
   }

modules/api/src/test/scala/de/nowchess/api/board/PieceTypeTest.scala

@@ -5,26 +5,16 @@ import org.scalatest.matchers.should.Matchers
 
 class PieceTypeTest extends AnyFunSuite with Matchers:
 
-  test("Pawn.label returns 'Pawn'") {
-    PieceType.Pawn.label shouldBe "Pawn"
-  }
+  test("PieceType values expose the expected labels"):
+    val expectedLabels = List(
+      PieceType.Pawn   -> "Pawn",
+      PieceType.Knight -> "Knight",
+      PieceType.Bishop -> "Bishop",
+      PieceType.Rook   -> "Rook",
+      PieceType.Queen  -> "Queen",
+      PieceType.King   -> "King",
+    )
 
-  test("Knight.label returns 'Knight'") {
-    PieceType.Knight.label shouldBe "Knight"
-  }
-
-  test("Bishop.label returns 'Bishop'") {
-    PieceType.Bishop.label shouldBe "Bishop"
-  }
-
-  test("Rook.label returns 'Rook'") {
-    PieceType.Rook.label shouldBe "Rook"
-  }
-
-  test("Queen.label returns 'Queen'") {
-    PieceType.Queen.label shouldBe "Queen"
-  }
-
-  test("King.label returns 'King'") {
-    PieceType.King.label shouldBe "King"
-  }
+    expectedLabels.foreach { (pieceType, expectedLabel) =>
+      pieceType.label shouldBe expectedLabel
+    }

modules/api/src/test/scala/de/nowchess/api/board/SquareTest.scala

@@ -5,58 +5,32 @@ import org.scalatest.matchers.should.Matchers
 
 class SquareTest extends AnyFunSuite with Matchers:
 
-  test("Square.toString produces lowercase file and rank number") {
-    Square(File.E, Rank.R4).toString shouldBe "e4"
-  }
-
-  test("Square.toString for a1") {
+  test("toString renders algebraic notation for edge and middle squares") {
     Square(File.A, Rank.R1).toString shouldBe "a1"
-  }
-
-  test("Square.toString for h8") {
+    Square(File.E, Rank.R4).toString shouldBe "e4"
     Square(File.H, Rank.R8).toString shouldBe "h8"
   }
 
-  test("fromAlgebraic parses valid square e4") {
-    Square.fromAlgebraic("e4") shouldBe Some(Square(File.E, Rank.R4))
+  test("fromAlgebraic parses valid coordinates including case-insensitive files") {
+    val expected = List(
+      "a1" -> Square(File.A, Rank.R1),
+      "e4" -> Square(File.E, Rank.R4),
+      "h8" -> Square(File.H, Rank.R8),
+      "E4" -> Square(File.E, Rank.R4),
+    )
+    expected.foreach { case (raw, sq) =>
+      Square.fromAlgebraic(raw) shouldBe Some(sq)
+    }
   }
 
-  test("fromAlgebraic parses valid square a1") {
-    Square.fromAlgebraic("a1") shouldBe Some(Square(File.A, Rank.R1))
+  test("fromAlgebraic rejects malformed coordinates") {
+    List("", "e", "e42", "z4", "ex", "e0", "e9").foreach { raw =>
+      Square.fromAlgebraic(raw) shouldBe None
+    }
   }
 
-  test("fromAlgebraic parses valid square h8") {
-    Square.fromAlgebraic("h8") shouldBe Some(Square(File.H, Rank.R8))
-  }
-
-  test("fromAlgebraic is case-insensitive for file") {
-    Square.fromAlgebraic("E4") shouldBe Some(Square(File.E, Rank.R4))
-  }
-
-  test("fromAlgebraic returns None for empty string") {
-    Square.fromAlgebraic("") shouldBe None
-  }
-
-  test("fromAlgebraic returns None for string too short") {
-    Square.fromAlgebraic("e") shouldBe None
-  }
-
-  test("fromAlgebraic returns None for string too long") {
-    Square.fromAlgebraic("e42") shouldBe None
-  }
-
-  test("fromAlgebraic returns None for invalid file character") {
-    Square.fromAlgebraic("z4") shouldBe None
-  }
-
-  test("fromAlgebraic returns None for non-digit rank") {
-    Square.fromAlgebraic("ex") shouldBe None
-  }
-
-  test("fromAlgebraic returns None for rank 0") {
-    Square.fromAlgebraic("e0") shouldBe None
-  }
-
-  test("fromAlgebraic returns None for rank 9") {
-    Square.fromAlgebraic("e9") shouldBe None
+  test("offset returns Some in-bounds and None out-of-bounds") {
+    Square(File.E, Rank.R4).offset(1, 2) shouldBe Some(Square(File.F, Rank.R6))
+    Square(File.A, Rank.R1).offset(-1, 0) shouldBe None
+    Square(File.H, Rank.R8).offset(0, 1) shouldBe None
   }

modules/api/src/test/scala/de/nowchess/api/game/GameContextTest.scala

@@ -0,0 +1,73 @@
+package de.nowchess.api.game
+
+import de.nowchess.api.board.{Board, CastlingRights, Color, File, Rank, Square}
+import de.nowchess.api.move.Move
+import de.nowchess.api.game.{DrawReason, GameResult}
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+
+class GameContextTest extends AnyFunSuite with Matchers:
+
+  test("GameContext.initial exposes expected default state"):
+    val initial = GameContext.initial
+
+    initial.board shouldBe Board.initial
+    initial.turn shouldBe Color.White
+    initial.castlingRights shouldBe CastlingRights.Initial
+    initial.enPassantSquare shouldBe None
+    initial.halfMoveClock shouldBe 0
+    initial.moves shouldBe List.empty
+    initial.result shouldBe None
+
+  test("withBoard updates only board"):
+    val square       = Square(File.E, Rank.R4)
+    val updatedBoard = Board.initial.updated(square, de.nowchess.api.board.Piece.WhiteQueen)
+    val updated      = GameContext.initial.withBoard(updatedBoard)
+    updated.board shouldBe updatedBoard
+    updated.turn shouldBe GameContext.initial.turn
+    updated.castlingRights shouldBe GameContext.initial.castlingRights
+    updated.enPassantSquare shouldBe GameContext.initial.enPassantSquare
+    updated.halfMoveClock shouldBe GameContext.initial.halfMoveClock
+    updated.moves shouldBe GameContext.initial.moves
+
+  test("withers update only targeted fields"):
+    val initial = GameContext.initial
+    val rights = CastlingRights(
+      whiteKingSide = true,
+      whiteQueenSide = false,
+      blackKingSide = false,
+      blackQueenSide = true,
+    )
+    val square        = Some(Square(File.E, Rank.R3))
+    val updatedTurn   = initial.withTurn(Color.Black)
+    val updatedRights = initial.withCastlingRights(rights)
+    val updatedEp     = initial.withEnPassantSquare(square)
+    val updatedClock  = initial.withHalfMoveClock(17)
+
+    updatedTurn.turn shouldBe Color.Black
+    updatedTurn.board shouldBe initial.board
+
+    updatedRights.castlingRights shouldBe rights
+    updatedRights.turn shouldBe initial.turn
+
+    updatedEp.enPassantSquare shouldBe square
+    updatedEp.castlingRights shouldBe initial.castlingRights
+
+    updatedClock.halfMoveClock shouldBe 17
+    updatedClock.moves shouldBe initial.moves
+
+  test("withMove appends move to history"):
+    val move = Move(Square(File.E, Rank.R2), Square(File.E, Rank.R4))
+    GameContext.initial.withMove(move).moves shouldBe List(move)
+
+  test("withResult sets Win result"):
+    val win = Some(GameResult.Win(Color.White))
+    GameContext.initial.withResult(win).result shouldBe win
+
+  test("withResult sets Draw result"):
+    val draw = Some(GameResult.Draw(DrawReason.Stalemate))
+    GameContext.initial.withResult(draw).result shouldBe draw
+
+  test("withResult clears result"):
+    val ctx = GameContext.initial.withResult(Some(GameResult.Win(Color.Black)))
+    ctx.withResult(None).result shouldBe None

modules/api/src/test/scala/de/nowchess/api/game/GameStateTest.scala

@@ -1,77 +0,0 @@
-package de.nowchess.api.game
-
-import de.nowchess.api.board.Color
-import org.scalatest.funsuite.AnyFunSuite
-import org.scalatest.matchers.should.Matchers
-
-class GameStateTest extends AnyFunSuite with Matchers:
-
-  test("CastlingRights.None has both flags false") {
-    CastlingRights.None.kingSide  shouldBe false
-    CastlingRights.None.queenSide shouldBe false
-  }
-
-  test("CastlingRights.Both has both flags true") {
-    CastlingRights.Both.kingSide  shouldBe true
-    CastlingRights.Both.queenSide shouldBe true
-  }
-
-  test("CastlingRights constructor sets fields") {
-    val cr = CastlingRights(kingSide = true, queenSide = false)
-    cr.kingSide  shouldBe true
-    cr.queenSide shouldBe false
-  }
-
-  test("GameResult cases exist") {
-    GameResult.WhiteWins shouldBe GameResult.WhiteWins
-    GameResult.BlackWins shouldBe GameResult.BlackWins
-    GameResult.Draw      shouldBe GameResult.Draw
-  }
-
-  test("GameStatus.NotStarted") {
-    GameStatus.NotStarted shouldBe GameStatus.NotStarted
-  }
-
-  test("GameStatus.InProgress") {
-    GameStatus.InProgress shouldBe GameStatus.InProgress
-  }
-
-  test("GameStatus.Finished carries result") {
-    val status = GameStatus.Finished(GameResult.Draw)
-    status shouldBe GameStatus.Finished(GameResult.Draw)
-    status match
-      case GameStatus.Finished(r) => r shouldBe GameResult.Draw
-      case _                      => fail("expected Finished")
-  }
-
-  test("GameState.initial has standard FEN piece placement") {
-    GameState.initial.piecePlacement shouldBe "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR"
-  }
-
-  test("GameState.initial active color is White") {
-    GameState.initial.activeColor shouldBe Color.White
-  }
-
-  test("GameState.initial white has full castling rights") {
-    GameState.initial.castlingWhite shouldBe CastlingRights.Both
-  }
-
-  test("GameState.initial black has full castling rights") {
-    GameState.initial.castlingBlack shouldBe CastlingRights.Both
-  }
-
-  test("GameState.initial en-passant target is None") {
-    GameState.initial.enPassantTarget shouldBe None
-  }
-
-  test("GameState.initial half-move clock is 0") {
-    GameState.initial.halfMoveClock shouldBe 0
-  }
-
-  test("GameState.initial full-move number is 1") {
-    GameState.initial.fullMoveNumber shouldBe 1
-  }
-
-  test("GameState.initial status is InProgress") {
-    GameState.initial.status shouldBe GameStatus.InProgress
-  }

modules/api/src/test/scala/de/nowchess/api/move/MoveTest.scala

@@ -9,48 +9,26 @@ class MoveTest extends AnyFunSuite with Matchers:
   private val e2 = Square(File.E, Rank.R2)
   private val e4 = Square(File.E, Rank.R4)
 
-  test("Move defaults moveType to Normal") {
-    val m = Move(e2, e4)
-    m.moveType shouldBe MoveType.Normal
-  }
-
-  test("Move stores from and to squares") {
+  test("Move defaults to Normal and keeps from/to squares") {
     val m = Move(e2, e4)
     m.from shouldBe e2
-    m.to   shouldBe e4
+    m.to shouldBe e4
+    m.moveType shouldBe MoveType.Normal()
   }
 
-  test("Move with CastleKingside moveType") {
-    val m = Move(e2, e4, MoveType.CastleKingside)
-    m.moveType shouldBe MoveType.CastleKingside
-  }
+  test("Move accepts all supported move types") {
+    val moveTypes = List(
+      MoveType.Normal(isCapture = true),
+      MoveType.CastleKingside,
+      MoveType.CastleQueenside,
+      MoveType.EnPassant,
+      MoveType.Promotion(PromotionPiece.Queen),
+      MoveType.Promotion(PromotionPiece.Rook),
+      MoveType.Promotion(PromotionPiece.Bishop),
+      MoveType.Promotion(PromotionPiece.Knight),
+    )
 
-  test("Move with CastleQueenside moveType") {
-    val m = Move(e2, e4, MoveType.CastleQueenside)
-    m.moveType shouldBe MoveType.CastleQueenside
-  }
-
-  test("Move with EnPassant moveType") {
-    val m = Move(e2, e4, MoveType.EnPassant)
-    m.moveType shouldBe MoveType.EnPassant
-  }
-
-  test("Move with Promotion to Queen") {
-    val m = Move(e2, e4, MoveType.Promotion(PromotionPiece.Queen))
-    m.moveType shouldBe MoveType.Promotion(PromotionPiece.Queen)
-  }
-
-  test("Move with Promotion to Knight") {
-    val m = Move(e2, e4, MoveType.Promotion(PromotionPiece.Knight))
-    m.moveType shouldBe MoveType.Promotion(PromotionPiece.Knight)
-  }
-
-  test("Move with Promotion to Bishop") {
-    val m = Move(e2, e4, MoveType.Promotion(PromotionPiece.Bishop))
-    m.moveType shouldBe MoveType.Promotion(PromotionPiece.Bishop)
-  }
-
-  test("Move with Promotion to Rook") {
-    val m = Move(e2, e4, MoveType.Promotion(PromotionPiece.Rook))
-    m.moveType shouldBe MoveType.Promotion(PromotionPiece.Rook)
+    moveTypes.foreach { moveType =>
+      Move(e2, e4, moveType).moveType shouldBe moveType
+    }
   }

modules/api/src/test/scala/de/nowchess/api/player/PlayerInfoTest.scala

@@ -5,19 +5,14 @@ import org.scalatest.matchers.should.Matchers
 
 class PlayerInfoTest extends AnyFunSuite with Matchers:
 
-  test("PlayerId.apply wraps a string") {
-    val id = PlayerId("player-123")
-    id.value shouldBe "player-123"
-  }
+  test("PlayerId and PlayerInfo preserve constructor values") {
+    val raw = "player-123"
+    val id  = PlayerId(raw)
 
-  test("PlayerId.value unwraps to original string") {
-    val raw = "abc-456"
-    PlayerId(raw).value shouldBe raw
-  }
+    id.value shouldBe raw
 
-  test("PlayerInfo holds id and displayName") {
-    val id   = PlayerId("p1")
-    val info = PlayerInfo(id, "Magnus")
-    info.id.value      shouldBe "p1"
-    info.displayName   shouldBe "Magnus"
+    val playerId = PlayerId("p1")
+    val info     = PlayerInfo(playerId, "Magnus")
+    info.id.value shouldBe "p1"
+    info.displayName shouldBe "Magnus"
   }

modules/api/src/test/scala/de/nowchess/api/response/ApiResponseTest.scala

@@ -5,58 +5,32 @@ import org.scalatest.matchers.should.Matchers
 
 class ApiResponseTest extends AnyFunSuite with Matchers:
 
-  test("ApiResponse.Success carries data") {
+  test("ApiResponse factories and payload wrappers keep values") {
     val r = ApiResponse.Success(42)
     r.data shouldBe 42
-  }
 
-  test("ApiResponse.Failure carries error list") {
     val err = ApiError("CODE", "msg")
-    val r   = ApiResponse.Failure(List(err))
-    r.errors shouldBe List(err)
-  }
+    ApiResponse.Failure(List(err)).errors shouldBe List(err)
+    ApiResponse.error(err) shouldBe ApiResponse.Failure(List(err))
 
-  test("ApiResponse.error creates single-error Failure") {
-    val err = ApiError("NOT_FOUND", "not found")
-    val f   = ApiResponse.error(err)
-    f shouldBe ApiResponse.Failure(List(err))
-  }
-
-  test("ApiError holds code and message") {
     val e = ApiError("CODE", "message")
-    e.code    shouldBe "CODE"
+    e.code shouldBe "CODE"
     e.message shouldBe "message"
-    e.field   shouldBe None
+    e.field shouldBe None
+    ApiError("INVALID", "bad value", Some("email")).field shouldBe Some("email")
   }
 
-  test("ApiError holds optional field") {
-    val e = ApiError("INVALID", "bad value", Some("email"))
-    e.field shouldBe Some("email")
-  }
-
-  test("Pagination.totalPages with exact division") {
+  test("Pagination.totalPages handles normal and guarded inputs") {
     Pagination(page = 0, pageSize = 10, totalItems = 30).totalPages shouldBe 3
-  }
-
-  test("Pagination.totalPages rounds up") {
     Pagination(page = 0, pageSize = 10, totalItems = 25).totalPages shouldBe 3
-  }
-
-  test("Pagination.totalPages is 0 when totalItems is 0") {
     Pagination(page = 0, pageSize = 10, totalItems = 0).totalPages shouldBe 0
-  }
-
-  test("Pagination.totalPages is 0 when pageSize is 0") {
     Pagination(page = 0, pageSize = 0, totalItems = 100).totalPages shouldBe 0
-  }
-
-  test("Pagination.totalPages is 0 when pageSize is negative") {
     Pagination(page = 0, pageSize = -1, totalItems = 100).totalPages shouldBe 0
   }
 
   test("PagedResponse holds items and pagination") {
     val pagination = Pagination(page = 1, pageSize = 5, totalItems = 20)
     val pr         = PagedResponse(List("a", "b"), pagination)
-    pr.items      shouldBe List("a", "b")
+    pr.items shouldBe List("a", "b")
     pr.pagination shouldBe pagination
   }

modules/api/versions.env

@@ -1,3 +1,3 @@
 MAJOR=0
-MINOR=0
-PATCH=6
+MINOR=4
+PATCH=0

modules/core/CHANGELOG.md

@@ -99,3 +99,139 @@
 * correct test board positions and captureOutput/withInput interaction ([f0481e2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f0481e2561b779df00925b46ee281dc36a795150))
 * update main class path in build configuration and adjust VCS directory mapping ([7b1f8b1](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7b1f8b117623d327232a1a92a8a44d18582e0189))
 * update move validation to check for king safety ([#13](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/13)) ([e5e20c5](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/e5e20c566e368b12ca1dc59680c34e9112bf6762))
+##  (2026-04-01)
+
+### Features
+
+* add GameRules stub with PositionStatus enum ([76d4168](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/76d4168038de23e5d6083d4e8f0504fbf31d15a3))
+* add MovedInCheck/Checkmate/Stalemate MoveResult variants (stub dispatch) ([8b7ec57](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/8b7ec57e5ea6ee1615a1883848a426dc07d26364))
+* implement GameRules with isInCheck, legalMoves, gameStatus ([94a02ff](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/94a02ff6849436d9496c70a0f16c21666dae8e4e))
+* implement legal castling ([#1](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/1)) ([00d326c](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/00d326c1ba67711fbe180f04e1100c3f01dd0254))
+* NCS-10 Implement Pawn Promotion ([#12](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/12)) ([13bfc16](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/13bfc16cfe25db78ec607db523ca6d993c13430c))
+* NCS-11 50-move rule ([#9](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/9)) ([412ed98](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/412ed986a95703a3b282276540153480ceed229d))
+* NCS-16 Core Separation via Patterns ([#10](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/10)) ([1361dfc](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/1361dfc89553b146864fb8ff3526cf12cf3f293a))
+* NCS-6 Implementing FEN & PGN ([#7](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/7)) ([f28e69d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f28e69dc181416aa2f221fdc4b45c2cda5efbf07))
+* NCS-9 En passant implementation ([#8](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/8)) ([919beb3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/919beb3b4bfa8caf2f90976a415fe9b19b7e9747))
+* wire check/checkmate/stalemate into processMove and gameLoop ([5264a22](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5264a225418b885c5e6ea6411b96f85e38837f6c))
+
+### Bug Fixes
+
+* add missing kings to gameLoop capture test board ([aedd787](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/aedd787b77203c2af934751dba7b784eaf165032))
+* correct test board positions and captureOutput/withInput interaction ([f0481e2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f0481e2561b779df00925b46ee281dc36a795150))
+* update main class path in build configuration and adjust VCS directory mapping ([7b1f8b1](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7b1f8b117623d327232a1a92a8a44d18582e0189))
+* update move validation to check for king safety ([#13](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/13)) ([e5e20c5](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/e5e20c566e368b12ca1dc59680c34e9112bf6762))
+##  (2026-04-01)
+
+### Features
+
+* add GameRules stub with PositionStatus enum ([76d4168](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/76d4168038de23e5d6083d4e8f0504fbf31d15a3))
+* add MovedInCheck/Checkmate/Stalemate MoveResult variants (stub dispatch) ([8b7ec57](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/8b7ec57e5ea6ee1615a1883848a426dc07d26364))
+* implement GameRules with isInCheck, legalMoves, gameStatus ([94a02ff](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/94a02ff6849436d9496c70a0f16c21666dae8e4e))
+* implement legal castling ([#1](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/1)) ([00d326c](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/00d326c1ba67711fbe180f04e1100c3f01dd0254))
+* NCS-10 Implement Pawn Promotion ([#12](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/12)) ([13bfc16](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/13bfc16cfe25db78ec607db523ca6d993c13430c))
+* NCS-11 50-move rule ([#9](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/9)) ([412ed98](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/412ed986a95703a3b282276540153480ceed229d))
+* NCS-16 Core Separation via Patterns ([#10](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/10)) ([1361dfc](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/1361dfc89553b146864fb8ff3526cf12cf3f293a))
+* NCS-17 Implement basic ScalaFX UI ([#14](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/14)) ([3ff8031](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/3ff80318b4f16c59733a46498581a5c27f048287))
+* NCS-6 Implementing FEN & PGN ([#7](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/7)) ([f28e69d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f28e69dc181416aa2f221fdc4b45c2cda5efbf07))
+* NCS-9 En passant implementation ([#8](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/8)) ([919beb3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/919beb3b4bfa8caf2f90976a415fe9b19b7e9747))
+* wire check/checkmate/stalemate into processMove and gameLoop ([5264a22](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5264a225418b885c5e6ea6411b96f85e38837f6c))
+
+### Bug Fixes
+
+* add missing kings to gameLoop capture test board ([aedd787](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/aedd787b77203c2af934751dba7b784eaf165032))
+* correct test board positions and captureOutput/withInput interaction ([f0481e2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f0481e2561b779df00925b46ee281dc36a795150))
+* update main class path in build configuration and adjust VCS directory mapping ([7b1f8b1](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7b1f8b117623d327232a1a92a8a44d18582e0189))
+* update move validation to check for king safety ([#13](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/13)) ([e5e20c5](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/e5e20c566e368b12ca1dc59680c34e9112bf6762))
+##  (2026-04-02)
+
+### Features
+
+* add GameRules stub with PositionStatus enum ([76d4168](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/76d4168038de23e5d6083d4e8f0504fbf31d15a3))
+* add MovedInCheck/Checkmate/Stalemate MoveResult variants (stub dispatch) ([8b7ec57](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/8b7ec57e5ea6ee1615a1883848a426dc07d26364))
+* implement GameRules with isInCheck, legalMoves, gameStatus ([94a02ff](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/94a02ff6849436d9496c70a0f16c21666dae8e4e))
+* implement legal castling ([#1](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/1)) ([00d326c](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/00d326c1ba67711fbe180f04e1100c3f01dd0254))
+* NCS-10 Implement Pawn Promotion ([#12](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/12)) ([13bfc16](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/13bfc16cfe25db78ec607db523ca6d993c13430c))
+* NCS-11 50-move rule ([#9](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/9)) ([412ed98](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/412ed986a95703a3b282276540153480ceed229d))
+* NCS-16 Core Separation via Patterns ([#10](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/10)) ([1361dfc](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/1361dfc89553b146864fb8ff3526cf12cf3f293a))
+* NCS-17 Implement basic ScalaFX UI ([#14](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/14)) ([3ff8031](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/3ff80318b4f16c59733a46498581a5c27f048287))
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+* NCS-6 Implementing FEN & PGN ([#7](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/7)) ([f28e69d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f28e69dc181416aa2f221fdc4b45c2cda5efbf07))
+* NCS-9 En passant implementation ([#8](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/8)) ([919beb3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/919beb3b4bfa8caf2f90976a415fe9b19b7e9747))
+* wire check/checkmate/stalemate into processMove and gameLoop ([5264a22](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5264a225418b885c5e6ea6411b96f85e38837f6c))
+
+### Bug Fixes
+
+* add missing kings to gameLoop capture test board ([aedd787](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/aedd787b77203c2af934751dba7b784eaf165032))
+* correct test board positions and captureOutput/withInput interaction ([f0481e2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f0481e2561b779df00925b46ee281dc36a795150))
+* update main class path in build configuration and adjust VCS directory mapping ([7b1f8b1](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7b1f8b117623d327232a1a92a8a44d18582e0189))
+* update move validation to check for king safety ([#13](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/13)) ([e5e20c5](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/e5e20c566e368b12ca1dc59680c34e9112bf6762))
+##  (2026-04-03)
+
+### Features
+
+* add GameRules stub with PositionStatus enum ([76d4168](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/76d4168038de23e5d6083d4e8f0504fbf31d15a3))
+* add MovedInCheck/Checkmate/Stalemate MoveResult variants (stub dispatch) ([8b7ec57](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/8b7ec57e5ea6ee1615a1883848a426dc07d26364))
+* implement GameRules with isInCheck, legalMoves, gameStatus ([94a02ff](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/94a02ff6849436d9496c70a0f16c21666dae8e4e))
+* implement legal castling ([#1](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/1)) ([00d326c](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/00d326c1ba67711fbe180f04e1100c3f01dd0254))
+* NCS-10 Implement Pawn Promotion ([#12](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/12)) ([13bfc16](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/13bfc16cfe25db78ec607db523ca6d993c13430c))
+* NCS-11 50-move rule ([#9](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/9)) ([412ed98](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/412ed986a95703a3b282276540153480ceed229d))
+* NCS-16 Core Separation via Patterns ([#10](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/10)) ([1361dfc](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/1361dfc89553b146864fb8ff3526cf12cf3f293a))
+* NCS-17 Implement basic ScalaFX UI ([#14](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/14)) ([3ff8031](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/3ff80318b4f16c59733a46498581a5c27f048287))
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+* NCS-6 Implementing FEN & PGN ([#7](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/7)) ([f28e69d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f28e69dc181416aa2f221fdc4b45c2cda5efbf07))
+* NCS-9 En passant implementation ([#8](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/8)) ([919beb3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/919beb3b4bfa8caf2f90976a415fe9b19b7e9747))
+* wire check/checkmate/stalemate into processMove and gameLoop ([5264a22](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5264a225418b885c5e6ea6411b96f85e38837f6c))
+
+### Bug Fixes
+
+* add missing kings to gameLoop capture test board ([aedd787](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/aedd787b77203c2af934751dba7b784eaf165032))
+* correct test board positions and captureOutput/withInput interaction ([f0481e2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f0481e2561b779df00925b46ee281dc36a795150))
+* update main class path in build configuration and adjust VCS directory mapping ([7b1f8b1](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7b1f8b117623d327232a1a92a8a44d18582e0189))
+* update move validation to check for king safety ([#13](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/13)) ([e5e20c5](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/e5e20c566e368b12ca1dc59680c34e9112bf6762))
+##  (2026-04-07)
+
+### Features
+
+* add GameRules stub with PositionStatus enum ([76d4168](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/76d4168038de23e5d6083d4e8f0504fbf31d15a3))
+* add MovedInCheck/Checkmate/Stalemate MoveResult variants (stub dispatch) ([8b7ec57](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/8b7ec57e5ea6ee1615a1883848a426dc07d26364))
+* implement GameRules with isInCheck, legalMoves, gameStatus ([94a02ff](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/94a02ff6849436d9496c70a0f16c21666dae8e4e))
+* implement legal castling ([#1](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/1)) ([00d326c](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/00d326c1ba67711fbe180f04e1100c3f01dd0254))
+* NCS-10 Implement Pawn Promotion ([#12](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/12)) ([13bfc16](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/13bfc16cfe25db78ec607db523ca6d993c13430c))
+* NCS-11 50-move rule ([#9](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/9)) ([412ed98](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/412ed986a95703a3b282276540153480ceed229d))
+* NCS-16 Core Separation via Patterns ([#10](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/10)) ([1361dfc](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/1361dfc89553b146864fb8ff3526cf12cf3f293a))
+* NCS-17 Implement basic ScalaFX UI ([#14](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/14)) ([3ff8031](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/3ff80318b4f16c59733a46498581a5c27f048287))
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+* NCS-6 Implementing FEN & PGN ([#7](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/7)) ([f28e69d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f28e69dc181416aa2f221fdc4b45c2cda5efbf07))
+* NCS-9 En passant implementation ([#8](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/8)) ([919beb3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/919beb3b4bfa8caf2f90976a415fe9b19b7e9747))
+* wire check/checkmate/stalemate into processMove and gameLoop ([5264a22](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5264a225418b885c5e6ea6411b96f85e38837f6c))
+
+### Bug Fixes
+
+* add missing kings to gameLoop capture test board ([aedd787](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/aedd787b77203c2af934751dba7b784eaf165032))
+* correct test board positions and captureOutput/withInput interaction ([f0481e2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f0481e2561b779df00925b46ee281dc36a795150))
+* update main class path in build configuration and adjust VCS directory mapping ([7b1f8b1](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7b1f8b117623d327232a1a92a8a44d18582e0189))
+* update move validation to check for king safety ([#13](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/13)) ([e5e20c5](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/e5e20c566e368b12ca1dc59680c34e9112bf6762))
+##  (2026-04-12)
+
+### Features
+
+* add GameRules stub with PositionStatus enum ([76d4168](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/76d4168038de23e5d6083d4e8f0504fbf31d15a3))
+* add MovedInCheck/Checkmate/Stalemate MoveResult variants (stub dispatch) ([8b7ec57](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/8b7ec57e5ea6ee1615a1883848a426dc07d26364))
+* implement GameRules with isInCheck, legalMoves, gameStatus ([94a02ff](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/94a02ff6849436d9496c70a0f16c21666dae8e4e))
+* implement legal castling ([#1](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/1)) ([00d326c](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/00d326c1ba67711fbe180f04e1100c3f01dd0254))
+* NCS-10 Implement Pawn Promotion ([#12](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/12)) ([13bfc16](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/13bfc16cfe25db78ec607db523ca6d993c13430c))
+* NCS-11 50-move rule ([#9](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/9)) ([412ed98](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/412ed986a95703a3b282276540153480ceed229d))
+* NCS-16 Core Separation via Patterns ([#10](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/10)) ([1361dfc](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/1361dfc89553b146864fb8ff3526cf12cf3f293a))
+* NCS-17 Implement basic ScalaFX UI ([#14](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/14)) ([3ff8031](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/3ff80318b4f16c59733a46498581a5c27f048287))
+* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
+* NCS-25 Add linters to keep quality up ([#27](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/27)) ([fd4e67d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/fd4e67d4f782a7e955822d90cb909d0a81676fb2))
+* NCS-6 Implementing FEN & PGN ([#7](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/7)) ([f28e69d](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f28e69dc181416aa2f221fdc4b45c2cda5efbf07))
+* NCS-9 En passant implementation ([#8](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/8)) ([919beb3](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/919beb3b4bfa8caf2f90976a415fe9b19b7e9747))
+* wire check/checkmate/stalemate into processMove and gameLoop ([5264a22](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/5264a225418b885c5e6ea6411b96f85e38837f6c))
+
+### Bug Fixes
+
+* add missing kings to gameLoop capture test board ([aedd787](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/aedd787b77203c2af934751dba7b784eaf165032))
+* correct test board positions and captureOutput/withInput interaction ([f0481e2](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/f0481e2561b779df00925b46ee281dc36a795150))
+* update main class path in build configuration and adjust VCS directory mapping ([7b1f8b1](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/7b1f8b117623d327232a1a92a8a44d18582e0189))
+* update move validation to check for king safety ([#13](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/13)) ([e5e20c5](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/e5e20c566e368b12ca1dc59680c34e9112bf6762))

modules/core/build.gradle.kts

@@ -1,7 +1,6 @@
 plugins {
     id("scala")
     id("org.scoverage") version "8.1"
-    application
 }
 
 group = "de.nowchess"
@@ -22,19 +21,10 @@ scoverage {
     scoverageVersion.set(versions["SCOVERAGE"]!!)
 }
 
-application {
-    mainClass.set("de.nowchess.chess.Main")
-}
-
 tasks.withType<ScalaCompile> {
     scalaCompileOptions.additionalParameters = listOf("-encoding", "UTF-8")
 }
 
-tasks.named<JavaExec>("run") {
-    jvmArgs("-Dfile.encoding=UTF-8", "-Dstdout.encoding=UTF-8", "-Dstderr.encoding=UTF-8")
-    standardInput = System.`in`
-}
-
 dependencies {
 
     implementation("org.scala-lang:scala3-compiler_3") {
@@ -49,6 +39,8 @@ dependencies {
     }
 
     implementation(project(":modules:api"))
+    implementation(project(":modules:io"))
+    implementation(project(":modules:rule"))
 
     testImplementation(platform("org.junit:junit-bom:5.13.4"))
     testImplementation("org.junit.jupiter:junit-jupiter")
@@ -62,7 +54,7 @@ tasks.test {
     useJUnitPlatform {
         includeEngines("scalatest")
         testLogging {
-            events("passed", "skipped", "failed")
+            events("skipped", "failed")
         }
     }
     finalizedBy(tasks.reportScoverage)

modules/core/src/main/scala/de/nowchess/chess/command/Command.scala

@@ -1,11 +1,11 @@
 package de.nowchess.chess.command
 
-import de.nowchess.api.board.{Square, Board, Color, Piece}
-import de.nowchess.chess.logic.GameHistory
+import de.nowchess.api.board.{Piece, Square}
+import de.nowchess.api.game.GameContext
 
-/** Marker trait for all commands that can be executed and undone.
- *  Commands encapsulate user actions and game state transitions.
- */
+/** Marker trait for all commands that can be executed and undone. Commands encapsulate user actions and game state
+  * transitions.
+  */
 trait Command:
   /** Execute the command and return true if successful, false otherwise. */
   def execute(): Boolean
@@ -16,49 +16,45 @@ trait Command:
   /** A human-readable description of this command. */
   def description: String
 
-/** Command to move a piece from one square to another.
- *  Stores the move result so undo can restore previous state.
- */
+/** Command to move a piece from one square to another. Stores the move result so undo can restore previous state.
+  */
 case class MoveCommand(
-  from: Square,
-  to: Square,
-  moveResult: Option[MoveResult] = None,
-  previousBoard: Option[Board] = None,
-  previousHistory: Option[GameHistory] = None,
-  previousTurn: Option[Color] = None
+    from: Square,
+    to: Square,
+    moveResult: Option[MoveResult] = None,
+    previousContext: Option[GameContext] = None,
+    notation: String = "",
 ) extends Command:
 
   override def execute(): Boolean =
     moveResult.isDefined
 
   override def undo(): Boolean =
-    previousBoard.isDefined && previousHistory.isDefined && previousTurn.isDefined
+    previousContext.isDefined
 
   override def description: String = s"Move from $from to $to"
 
 // Sealed hierarchy of move outcomes (for tracking state changes)
 sealed trait MoveResult
 object MoveResult:
-  case class Successful(newBoard: Board, newHistory: GameHistory, newTurn: Color, captured: Option[Piece]) extends MoveResult
-  case object InvalidFormat extends MoveResult
-  case object InvalidMove extends MoveResult
+  case class Successful(newContext: GameContext, captured: Option[Piece]) extends MoveResult
+  case object InvalidFormat                                               extends MoveResult
+  case object InvalidMove                                                 extends MoveResult
 
 /** Command to quit the game. */
 case class QuitCommand() extends Command:
-  override def execute(): Boolean = true
-  override def undo(): Boolean = false
+  override def execute(): Boolean  = true
+  override def undo(): Boolean     = false
   override def description: String = "Quit game"
 
 /** Command to reset the board to initial position. */
 case class ResetCommand(
-  previousBoard: Option[Board] = None,
-  previousHistory: Option[GameHistory] = None,
-  previousTurn: Option[Color] = None
+    previousContext: Option[GameContext] = None,
 ) extends Command:
 
   override def execute(): Boolean = true
 
   override def undo(): Boolean =
-    previousBoard.isDefined && previousHistory.isDefined && previousTurn.isDefined
+    previousContext.isDefined
 
   override def description: String = "Reset board"

modules/core/src/main/scala/de/nowchess/chess/command/CommandInvoker.scala

@@ -3,21 +3,19 @@ package de.nowchess.chess.command
 /** Manages command execution and history for undo/redo support. */
 class CommandInvoker:
   private val executedCommands = scala.collection.mutable.ListBuffer[Command]()
+  @SuppressWarnings(Array("DisableSyntax.var"))
   private var currentIndex = -1
 
-  /** Execute a command and add it to history.
-   *  Discards any redo history if not at the end of the stack.
-   */
+  /** Execute a command and add it to history. Discards any redo history if not at the end of the stack.
+    */
   def execute(command: Command): Boolean = synchronized {
     if command.execute() then
       // Remove any commands after current index (redo stack is discarded)
-      while currentIndex < executedCommands.size - 1 do
-        executedCommands.remove(executedCommands.size - 1)
+      while currentIndex < executedCommands.size - 1 do executedCommands.remove(executedCommands.size - 1)
       executedCommands += command
       currentIndex += 1
       true
-    else
-      false
+    else false
   }
 
   /** Undo the last executed command if possible. */
@@ -27,10 +25,8 @@ class CommandInvoker:
       if command.undo() then
         currentIndex -= 1
         true
-      else
-        false
-    else
-      false
+      else false
+    else false
   }
 
   /** Redo the next command in history if available. */
@@ -40,10 +36,8 @@ class CommandInvoker:
       if command.execute() then
         currentIndex += 1
         true
-      else
-        false
-    else
-      false
+      else false
+    else false
   }
 
   /** Get the history of all executed commands. */

modules/core/src/main/scala/de/nowchess/chess/controller/GameController.scala

@@ -1,105 +0,0 @@
-package de.nowchess.chess.controller
-
-import de.nowchess.api.board.{Board, Color, File, Piece, PieceType, Rank, Square}
-import de.nowchess.api.move.PromotionPiece
-import de.nowchess.chess.logic.*
-
-// ---------------------------------------------------------------------------
-// Result ADT returned by the pure processMove function
-// ---------------------------------------------------------------------------
-
-sealed trait MoveResult
-object MoveResult:
-  case object Quit                                                                       extends MoveResult
-  case class  InvalidFormat(raw: String)                                                extends MoveResult
-  case object NoPiece                                                                   extends MoveResult
-  case object WrongColor                                                                extends MoveResult
-  case object IllegalMove                                                               extends MoveResult
-  case class  PromotionRequired(
-    from: Square,
-    to: Square,
-    boardBefore: Board,
-    historyBefore: GameHistory,
-    captured: Option[Piece],
-    turn: Color
-  ) extends MoveResult
-  case class  Moved(newBoard: Board, newHistory: GameHistory, captured: Option[Piece], newTurn: Color)      extends MoveResult
-  case class  MovedInCheck(newBoard: Board, newHistory: GameHistory, captured: Option[Piece], newTurn: Color) extends MoveResult
-  case class  Checkmate(winner: Color)                                                  extends MoveResult
-  case object Stalemate                                                                 extends MoveResult
-
-// ---------------------------------------------------------------------------
-// Controller
-// ---------------------------------------------------------------------------
-
-object GameController:
-
-  /** Pure function: interprets one raw input line against the current game context.
-   *  Has no I/O side effects — all output must be handled by the caller.
-   */
-  def processMove(board: Board, history: GameHistory, turn: Color, raw: String): MoveResult =
-    raw.trim match
-      case "quit" | "q" => MoveResult.Quit
-      case trimmed =>
-        Parser.parseMove(trimmed) match
-          case None              => MoveResult.InvalidFormat(trimmed)
-          case Some((from, to))  => validateAndApply(board, history, turn, from, to)
-
-  /** Apply a previously detected promotion move with the chosen piece.
-   *  Called after processMove returned PromotionRequired.
-   */
-  def completePromotion(
-    board: Board,
-    history: GameHistory,
-    from: Square,
-    to: Square,
-    piece: PromotionPiece,
-    turn: Color
-  ): MoveResult =
-    val (boardAfterMove, captured) = board.withMove(from, to)
-    val promotedPieceType = piece match
-      case PromotionPiece.Queen  => PieceType.Queen
-      case PromotionPiece.Rook   => PieceType.Rook
-      case PromotionPiece.Bishop => PieceType.Bishop
-      case PromotionPiece.Knight => PieceType.Knight
-    val newBoard    = boardAfterMove.updated(to, Piece(turn, promotedPieceType))
-    // Promotion is always a pawn move → clock resets
-    val newHistory = history.addMove(from, to, None, Some(piece), wasPawnMove = true)
-    toMoveResult(newBoard, newHistory, captured, turn)
-
-  // ---------------------------------------------------------------------------
-  // Private helpers
-  // ---------------------------------------------------------------------------
-
-  private def validateAndApply(board: Board, history: GameHistory, turn: Color, from: Square, to: Square): MoveResult =
-    board.pieceAt(from) match
-      case None                              => MoveResult.NoPiece
-      case Some(piece) if piece.color != turn => MoveResult.WrongColor
-      case Some(_) =>
-        if !GameRules.legalMoves(board, history, turn).contains(from -> to) then MoveResult.IllegalMove
-        else if MoveValidator.isPromotionMove(board, from, to) then
-          MoveResult.PromotionRequired(from, to, board, history, board.pieceAt(to), turn)
-        else applyNormalMove(board, history, turn, from, to)
-
-  private def applyNormalMove(board: Board, history: GameHistory, turn: Color, from: Square, to: Square): MoveResult =
-    val castleOpt              = Option.when(MoveValidator.isCastle(board, from, to))(MoveValidator.castleSide(from, to))
-    val isEP                   = EnPassantCalculator.isEnPassant(board, history, from, to)
-    val (newBoard, captured)   = castleOpt match
-      case Some(side) => (board.withCastle(turn, side), None)
-      case None =>
-        val (b, cap) = board.withMove(from, to)
-        if isEP then
-          val capturedSq = EnPassantCalculator.capturedPawnSquare(to, turn)
-          (b.removed(capturedSq), board.pieceAt(capturedSq))
-        else (b, cap)
-    val wasPawnMove = board.pieceAt(from).exists(_.pieceType == PieceType.Pawn)
-    val wasCapture  = captured.isDefined
-    val newHistory  = history.addMove(from, to, castleOpt, wasPawnMove = wasPawnMove, wasCapture = wasCapture)
-    toMoveResult(newBoard, newHistory, captured, turn)
-
-  private def toMoveResult(newBoard: Board, newHistory: GameHistory, captured: Option[Piece], turn: Color): MoveResult =
-    GameRules.gameStatus(newBoard, newHistory, turn.opposite) match
-      case PositionStatus.Normal  => MoveResult.Moved(newBoard, newHistory, captured, turn.opposite)
-      case PositionStatus.InCheck => MoveResult.MovedInCheck(newBoard, newHistory, captured, turn.opposite)
-      case PositionStatus.Mated   => MoveResult.Checkmate(turn)
-      case PositionStatus.Drawn   => MoveResult.Stalemate

modules/core/src/main/scala/de/nowchess/chess/controller/Parser.scala

@@ -4,21 +4,25 @@ import de.nowchess.api.board.{File, Rank, Square}
 
 object Parser:
 
-  /** Parses coordinate notation such as "e2e4" or "g1f3".
-   *  Returns None for any input that does not match the expected format.
-   */
+  /** Parses coordinate notation such as "e2e4" or "g1f3". Returns None for any input that does not match the expected
+    * format.
+    */
   def parseMove(input: String): Option[(Square, Square)] =
     val trimmed = input.trim.toLowerCase
-    Option.when(trimmed.length == 4)(trimmed).flatMap: s =>
-      for
-        from <- parseSquare(s.substring(0, 2))
-        to   <- parseSquare(s.substring(2, 4))
-      yield (from, to)
+    Option
+      .when(trimmed.length == 4)(trimmed)
+      .flatMap: s =>
+        for
+          from <- parseSquare(s.substring(0, 2))
+          to   <- parseSquare(s.substring(2, 4))
+        yield (from, to)
 
   private def parseSquare(s: String): Option[Square] =
-    Option.when(s.length == 2)(s).flatMap: sq =>
-      val fileIdx = sq(0) - 'a'
-      val rankIdx = sq(1) - '1'
-      Option.when(fileIdx >= 0 && fileIdx <= 7 && rankIdx >= 0 && rankIdx <= 7)(
-        Square(File.values(fileIdx), Rank.values(rankIdx))
-      )
+    Option
+      .when(s.length == 2)(s)
+      .flatMap: sq =>
+        val fileIdx = sq(0) - 'a'
+        val rankIdx = sq(1) - '1'
+        Option.when(fileIdx >= 0 && fileIdx <= 7 && rankIdx >= 0 && rankIdx <= 7)(
+          Square(File.values(fileIdx), Rank.values(rankIdx)),
+        )