feat: Enhance GameResource with game state validation and add comprehensive tests

CLAUDE.md

@@ -10,7 +10,7 @@ Scala 3.5.1 · Gradle 9
 ./test       # Run all tests
 ./coverage   # Check coverage
 ```
-Try to stick to these commands for consistency.
+Use consistently.
 
 ## Modules
 
@@ -25,14 +25,14 @@ Try to stick to these commands for consistency.
 
 ## 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.
+- Immutable data, pure functions.
+- Functions under 30 lines. Need "and"? Split it.
+- Cyclomatic complexity under 15.
+- No comments. Names carry intent. Comment non-obvious algorithms only.
+- Scan duplicated logic. Extract.
 - 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.
+- `Option`/`Either` for fallible ops. Skip exceptions for control flow.
+- Naming: types PascalCase, functions/values camelCase.
 
 ## Code Quality
 
@@ -40,23 +40,23 @@ Try to stick to these commands for consistency.
 
 ### 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.
+- **scalafmt** — Enforces formatting. Check: `./gradlew spotlessScalaCheck`. Refactor: `./gradlew spotlessScalaApply`.
+- **scalafix** — Enforces style, detects unused imports/code. Run: `./gradlew scalafix`.
 
 ## 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.
-- **Polyglot hash must follow spec index layout:** piece keys use interleaved mapping `(pieceType * 2 + colorBit)` with black=0/white=1, castling keys are `768..771`, en-passant file keys are `772..779` and are XORed only if side-to-move has a pawn that can capture en passant, side-to-move key is `780` for white.
-- **Alpha-beta uses sequential PV search by default:** parallel split was disabled because fixed-window futures removed pruning effectiveness; correctness and pruning quality take priority over speculative parallelism.
-- **Search hash is updated incrementally per move:** bot search now updates Zobrist keys from parent hash with move deltas instead of recomputing piece scans at every node.
+- **Immutable state as primary model:** GameContext (api) holds board, history, player state—immutable throughout. Each move → new GameContext. Enables undo/redo without side effects.
+- **Observer pattern for UI decoupling:** GameEngine publishes move/state events; CommandInvoker queues moves; UI listens (no polling). GameEngine never imports UI.
+- **RuleSet trait encapsulates rules:** Move generation, check, castling, en passant all in RuleSet impl. GameEngine calls rules as black box; rules don't know rest of core.
+- **Polyglot hash must follow spec index layout:** Piece keys use interleaved mapping `(pieceType * 2 + colorBit)` (black=0, white=1). Castling keys: `768..771`. En-passant file keys: `772..779`, XORed only if side-to-move has capturable en passant. Side-to-move key: `780` (white).
+- **Alpha-beta uses sequential PV search by default:** Parallel split disabled (fixed-window futures removed pruning effectiveness). Sequential PV default. Correctness + pruning quality > speculative parallelism.
+- **Search hash is updated incrementally per move:** Bot search updates Zobrist keys from parent hash with move deltas, not recomputing piece scans per node.
 
 ## Rules
 
-- **Tests are the spec.** Never modify tests to pass; modify requirements or code. Update tests only if requirements change.
+- **Tests are the spec.** Don't modify to pass. Fix requirements/code. Update only if requirements change.
 - Never read build folders. Ask permission if needed.
-- Keep this file up to date with any important decisions or conventions.
+- Keep file current with decisions + conventions.
 
 ---
 
@@ -64,11 +64,9 @@ Try to stick to these commands for consistency.
 
 ### 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.
+**Step 2 — Verify:** Read source files from wiki BEFORE coding.
 
-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.**
+Wiki = structural summaries (routes, models, file locations). No function logic, middleware internals, runtime behavior. Don't code from wiki alone—read sources.
 
 Read in order at session start:
 1. `.codesight/wiki/index.md` — orientation map (~200 tokens)
@@ -76,8 +74,7 @@ Read in order at session start:
 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.
+`[inferred]` routes = regex-detected. Verify sources. ⚠ in wiki? Re-run `codesight --wiki`.
 
 Or use the codesight MCP server for on-demand queries:
 - `codesight_get_wiki_article` — read a specific wiki article by name
@@ -87,13 +84,13 @@ Or use the codesight MCP server for on-demand queries:
 - `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.
+Consult codesight context first. Saves ~16.893 tokens/conversation.
 
 ## graphify
 
-This project has a graphify knowledge graph at graphify-out/.
+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
+- Architecture/codebase questions? Read graphify-out/GRAPH_REPORT.md (god nodes, communities).
+- graphify-out/wiki/index.md exists? Use it (not raw files).
+- Code modified? Run `python3 -c "from graphify.watch import _rebuild_code; from pathlib import Path; _rebuild_code(Path('.'))"` to sync graph.