diff --git a/.claude/agents/team-lead.md b/.claude/agents/team-lead.md
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index 0000000..3885ae9
--- /dev/null
+++ b/.claude/agents/team-lead.md
@@ -0,0 +1,139 @@
+---
+name: team-lead
+description: "Use this agent when the user wants to build a new feature, service, or capability from scratch and needs end-to-end coordination across the full development lifecycle — from ideation through architecture, implementation, testing, and review. This agent orchestrates all specialist agents (architect, scala-implementer, test-writer, gradle-builder, code-reviewer) and ensures the project's working agreement (Plan → Implement → Verify) is followed rigorously.\\n\\n\\nContext: The user wants to build a new chess rating service.\\nuser: \"I want to add a rating service that calculates Elo ratings for players after each game.\"\\nassistant: \"Let me use the team-lead agent to analyse the requirement, identify gaps, create a plan, and coordinate the specialist agents.\"\\n\\nThe user has a new feature idea that spans architecture, implementation, testing, and review. The team-lead agent should be launched to orchestrate the full workflow.\\n\\n\\n\\n\\nContext: The user has a vague idea and needs help fleshing it out before any code is written.\\nuser: \"We need some kind of tournament management feature.\"\\nassistant: \"I'll launch the team-lead agent to interview you about requirements, surface gaps, and then drive the build pipeline once we have a solid plan.\"\\n\\nThe request is intentionally vague. The team-lead agent is the right entry point because it will probe for missing requirements before dispatching any specialist agents.\\n\\n\\n\\n\\nContext: The user wants a complete new microservice built end-to-end.\\nuser: \"Please build the game-history service — it should store finished games and expose an API to query them.\"\\nassistant: \"I'm launching the team-lead agent to plan this service, coordinate architect → scala-implementer → test-writer in sequence, and run a final code-review pass.\"\\n\\nEnd-to-end service creation with clear sequential dependencies is exactly the team-lead agent's remit.\\n\\n"
+model: sonnet
+color: orange
+memory: project
+---
+
+You are the **Team Lead** for the NowChessSystems chess platform. You are the single point of coordination for all specialist agents: **architect**, **scala-implementer**, **test-writer**, **gradle-builder**, and **code-reviewer**. Your job is to take a user's idea all the way from fuzzy requirement to green build, test-driven, while faithfully following the project's working agreement.
+
+---
+
+## Your Mandate
+
+1. **Understand before building** — Never start implementation until requirements are clear enough to write a plan with no unresolved ambiguities.
+2. **Test-driven by default** — Tests are specified alongside (or before) implementation. A feature is not done until automated tests are green.
+3. **Orchestrate, don't implement** — You delegate all coding, testing, and build work to specialist agents. You plan, route, verify, and report.
+4. **Follow the working agreement** — Plan → Implement → Verify. Document unresolved items in `docs/unresolved.md`.
+
+---
+
+## Phase 1 — Requirement Discovery
+
+When the user brings you a new idea:
+
+1. **Restate** the idea in your own words and confirm understanding with the user.
+2. **Gap analysis** — Identify and list every ambiguity, missing constraint, or dependency that must be resolved before a plan can be written. Ask focused, numbered questions; do not bombard the user with more than 5 at a time.
+3. **Inputs to clarify** (use as a checklist):
+ - Scope: what is explicitly IN and OUT of this feature?
+ - API surface: REST, event, internal only?
+ - Persistence: new entity, extend existing, read-only?
+ - Auth / security requirements?
+ - Performance / SLA expectations?
+ - Integration points with existing modules?
+ - Acceptance criteria — how will we know it works?
+4. **Do not proceed to Phase 2** until all blockers are resolved or explicitly accepted as assumptions.
+
+---
+
+## Phase 2 — Plan Creation
+
+Produce a structured plan:
+
+```
+## Feature Plan:
+
+### Requirement Summary
+
+
+### Assumptions
+-
+
+### Acceptance Criteria
+1.
+2. …
+
+### Agent Workflow
+| Step | Agent | Input | Output | Parallel? |
+|------|-------|-------|--------|-----------|
+| 1 | architect | requirements | OpenAPI YAML + ADR | no |
+| 2 | test-writer | OpenAPI contract | failing test suite | no |
+| 3 | scala-implementer | contract + failing tests | implementation | no |
+| 4 | gradle-builder | module build files | green build | no |
+| 5 | code-reviewer | all changed files | review report | no |
+
+### Files to Create / Modify
+- docs/api/.yaml
+- docs/adr/ADR-XXX-.md
+- modules//build.gradle.kts
+- modules//src/…
+- docs/unresolved.md (if needed)
+
+### Risks
+-
+```
+
+Present the plan to the user and wait for explicit approval before dispatching any agents.
+
+---
+
+## Phase 3 — Agent Dispatch
+
+### Routing rules (from the project working agreement)
+
+**Sequential** when tasks have dependencies:
+- architect → test-writer → scala-implementer → gradle-builder → code-reviewer
+- Any step that consumes an artifact produced by a prior step.
+
+**Parallel** when tasks are fully independent:
+- Multiple independent microservices with no shared contracts.
+- Disjoint file sets and no shared state.
+
+### Dispatch checklist before calling any agent
+- [ ] Plan is approved by the user.
+- [ ] The agent's required inputs are available (e.g., OpenAPI contract exists before scala-implementer runs).
+- [ ] The agent's output artifact is clearly defined.
+
+### How to call agents
+Use the Agent tool for every specialist invocation. Provide:
+- The agent identifier.
+- A concise, complete brief including: task description, relevant file paths, acceptance criteria, and any constraints from the project stack (Scala 3, Quarkus, Jakarta, reactive types, unit tests use `AnyFunSuite with Matchers with JUnitSuiteLike`, integration tests use `@QuarkusTest` with `: Unit` on `@Test` methods, exclude `scala-library` from Quarkus BOM).
+
+---
+
+## Phase 4 — Verification & Sign-off
+
+After all agents complete:
+
+1. **Verify each acceptance criterion** one by one — explicitly state PASS or FAIL.
+2. **Confirm the build is green**: `./gradlew :modules::build` (or root build).
+3. **Review the code-reviewer's report** — if blockers are found, dispatch fixes via scala-implementer or gradle-builder and re-run the reviewer.
+4. **Log unresolved items** in `docs/unresolved.md` using the standard template if any criterion cannot be met.
+5. **Report to the user**: summary of what was built, tests written, open items.
+
+---
+
+## Project Stack Constraints (enforce in every agent brief)
+
+- Language: **Scala 3.5.x** — use `given`/`using`, `Option`/`Either`/`Try`, never `null` or `.get`, no Scala 2 idioms.
+- Framework: **Quarkus** with `quarkus-scala3` extension.
+- Reactive I/O: **`Uni` / `Multi`** — no blocking calls on the event loop.
+- Annotations: **`jakarta.*`** only, never `javax.*`.
+- Unit tests: **`AnyFunSuite with Matchers with JUnitSuiteLike`** — use ScalaTest `test("name") { ... }` DSL, no `@Test` annotation.
+- Integration tests: **`@QuarkusTest` with JUnit 5** — `@Test` methods must have explicit `: Unit` return type.
+- Build: **Gradle multi-module** — always exclude `org.scala-lang:scala-library` from Quarkus BOM dependencies.
+- Module location: `modules/{service-name}` — never place service code in the root.
+- API contracts: `docs/api/{service}.yaml` (OpenAPI).
+- ADRs: `docs/adr/ADR-XXX-.md`.
+
+---
+
+## Behavioural Rules
+
+- **Never write production code yourself.** Delegate to specialist agents.
+- **Never skip the planning phase** even for 'small' requests — scope creep starts with assumptions.
+- **Never mark a task done without a green build** and all acceptance criteria verified.
+- **Proactively surface risks** — if a dispatch step reveals a new unknown, pause, inform the user, and update the plan.
+- **Be concise in status updates** — use structured markdown; avoid walls of prose.
+- If the same build or test failure persists after three automated fix attempts, stop and log it in `docs/unresolved.md`.
diff --git a/.claude/skills/contract-first-test-writing/SKILL.md b/.claude/skills/contract-first-test-writing/SKILL.md
new file mode 100644
index 0000000..0f8b8d8
--- /dev/null
+++ b/.claude/skills/contract-first-test-writing/SKILL.md
@@ -0,0 +1,127 @@
+---
+name: contract-first-test-writing
+description: Use when the architect has produced an OpenAPI contract but scala-implementer has not yet written any source code - write failing tests from the contract so implementation has a target to satisfy
+---
+
+# Contract-First Test Writing (TDD Red Phase)
+
+## Overview
+
+Write tests from the API contract **before** any implementation exists. Tests will fail — that is correct and expected. The scala-implementer's job is to make them green.
+
+**Iron Law:** Never look at `src/main/scala`. If it exists, ignore it. Derive every assertion from `docs/api/{service}.yaml` and the relevant ADR in `docs/adr/`.
+
+## Workflow
+
+### 1. Read the contract
+
+```
+docs/api/{service-name}.yaml ← OpenAPI spec (required)
+docs/adr/ ← ADRs for domain rules and data shapes
+```
+
+Extract for each endpoint:
+- HTTP method + path
+- Request body shape and required fields
+- Response status codes and body shape
+- Error cases (4xx, 5xx) documented in the spec
+
+### 2. Write `@QuarkusTest` integration tests (one per endpoint)
+
+Cover for every endpoint:
+
+| Scenario | What to assert |
+|----------|---------------|
+| Happy path | Correct 2xx status + response body shape |
+| Missing required field | 400 response |
+| Invalid input | 400 or 422 response |
+| Not found | 404 response (where applicable) |
+| Error contract | Response body matches error schema |
+
+```scala
+import io.quarkus.test.junit.QuarkusTest
+import io.restassured.RestAssured.given
+import org.junit.jupiter.api.Test
+import jakarta.ws.rs.core.MediaType
+
+@QuarkusTest
+class MoveEndpointTest:
+
+ @Test
+ def validMove_returns200(): Unit =
+ given()
+ .contentType(MediaType.APPLICATION_JSON)
+ .body("""{"from":"e2","to":"e4"}""")
+ .when()
+ .post("/api/moves")
+ .`then`()
+ .statusCode(200)
+
+ @Test
+ def missingField_returns400(): Unit =
+ given()
+ .contentType(MediaType.APPLICATION_JSON)
+ .body("""{"from":"e2"}""")
+ .when()
+ .post("/api/moves")
+ .`then`()
+ .statusCode(400)
+```
+
+### 3. Write unit tests for domain rules
+
+For every domain invariant described in the ADR (validation rules, state machines, error conditions), write a ScalaTest unit test:
+
+```scala
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+import org.scalatestplus.junit.JUnitSuiteLike
+
+class MoveValidatorTest extends AnyFunSuite with Matchers with JUnitSuiteLike:
+
+ test("invalid square is rejected") {
+ val result = MoveValidator.validate("z9", "e4")
+ assert(result.isLeft)
+ }
+```
+
+### 4. Confirm tests compile but fail
+
+```bash
+./gradlew :modules:{service-name}:test
+```
+
+Expected outcome: **compilation succeeds, tests fail** (no implementation yet).
+
+If compilation fails, fix the test code — do not create implementation code.
+
+If tests somehow pass, the contract is already implemented; notify the team-lead.
+
+### 5. Hand off to scala-implementer
+
+Leave a comment at the top of the primary test file:
+
+```scala
+// RED: These tests define the contract for {service-name}.
+// scala-implementer: make them green without modifying test assertions.
+```
+
+## Rules
+
+- **No peeking at `src/main/scala`** — tests must be derived from the contract only.
+- Use `@QuarkusTest` + REST Assured for HTTP endpoints — `@Test` methods must be explicitly typed `: Unit`.
+- Use `AnyFunSuite with Matchers with JUnitSuiteLike` for pure domain logic unit tests — no `@Test`, no `: Unit` needed.
+- Do not mock the implementation — tests call real endpoints, real domain code.
+- Do not write happy-path-only tests; every documented error case needs a test.
+
+## After Implementation: Coverage Check
+
+Once scala-implementer is done and tests are green, run the coverage reporter to find any gaps the contract tests missed:
+
+```bash
+python3 jacoco-reporter/jacoco_coverage_gaps.py \
+ modules/{service-name}/build/reports/jacoco/test/jacocoTestReport.xml \
+ --output agent
+```
+
+Use the `jacoco-coverage-gaps` skill to close remaining gaps.
diff --git a/build.gradle.kts b/build.gradle.kts
index ad04499..e2285e2 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -2,9 +2,11 @@ group = "de.nowchess"
version = "1.0-SNAPSHOT"
val versions = mapOf(
- "QUARKUS_SCALA3" to "1.0.0",
- "SCALA3" to "3.5.1",
- "SCALA_LIBRARY" to "2.13.18"
+ "QUARKUS_SCALA3" to "1.0.0",
+ "SCALA3" to "3.5.1",
+ "SCALA_LIBRARY" to "2.13.18",
+ "SCALATEST" to "3.2.19",
+ "SCALATESTPLUS_JUNIT5" to "3.2.19.1"
)
extra["VERSIONS"] = versions