migrate: switch server test dependency from net.minestom:testing to Cyano

Description

The server module currently uses the upstream Minestom testing module (net.minestom:testing) for its test harness. The team maintains its own test framework — Cyano (net.onelitefeather:cyano, see OneLiteFeatherNET/Cyano) — which is the preferred replacement, delivered via the Mycelium BOM.

API surface change (minimal):

The Env interface (net.minestom.testing.Env) remains the same — test bodies need no logic changes, only the class-level annotation changes.

Affected Files

• settings.gradle.kts — version catalog entry minecraft.minestom.testing (line 25); add Cyano + Mycelium BOM entries
• server/build.gradle.kts — replace testImplementation(libs.minecraft.minestom.testing) with Cyano dependency
• 15 test files under server/src/test/ that carry @EnvTest:
  • net/elytrarace/server/VoyagerServerTest.java
  • net/elytrarace/server/ecs/GameEntityFactoryTest.java
  • net/elytrarace/server/ecs/component/HudComponentTest.java
  • net/elytrarace/server/ecs/system/ElytraPhysicsSystemTest.java
  • net/elytrarace/server/ecs/system/FireworkBoostSystemTest.java
  • net/elytrarace/server/ecs/system/OutOfBoundsSystemTest.java
  • net/elytrarace/server/ecs/system/RingCollisionSystemTest.java
  • net/elytrarace/server/ecs/system/RingEffectSystemTest.java
  • net/elytrarace/server/game/GameLoopSystemTest.java
  • net/elytrarace/server/game/GameOrchestratorTest.java
  • net/elytrarace/server/perf/EcsGameLoopLoadTest.java
  • net/elytrarace/server/phase/MinestomEndPhaseRankingTest.java
  • net/elytrarace/server/player/PlayerServiceTest.java
  • net/elytrarace/server/scoring/ScoringServiceTest.java
  • net/elytrarace/server/world/AnvilMapInstanceServiceTest.java

Acceptance Criteria

• settings.gradle.kts version catalog declares the Cyano library (via Mycelium BOM or explicit coordinates); minecraft.minestom.testing is removed or kept only if still required by another module
• server/build.gradle.kts uses Cyano as testImplementation instead of libs.minecraft.minestom.testing
• All 15 @EnvTest annotations are replaced with @ExtendWith(MicrotusExtension.class) (import: net.minestom.testing.extension.MicrotusExtension)
• ./gradlew :server:test passes with zero failures after migration
• CLAUDE.md is updated to document the Cyano testing pattern (replace any mention of @EnvTest / minestom.testing with the new pattern)

Technical Details

• Cyano coordinates: net.onelitefeather:cyano (check Mycelium BOM for the exact version pin)
• Env interface stays at net.minestom.testing.Env — no changes to test method signatures or injection points
• The version catalog in this project is defined programmatically in settings.gradle.kts under dependencyResolutionManagement { versionCatalogs { ... } } — do NOT create gradle/libs.versions.toml
• The existing aonyx-bom (net.onelitefeather:aonyx-bom:0.7.0) is already declared; check whether the Mycelium BOM is a separate artifact or already transitively included

Dependencies

None — this is a test-scope change only and does not affect production classpath or runtime behavior.

Estimate

S — mechanical find-and-replace across 15 files plus two build files; no logic changes required.

Start with the version catalog in settings.gradle.kts and the test dependency in server/build.gradle.kts, checking the Mycelium BOM for Cyano's version. Update the 15 listed server tests and review CLAUDE.md for the old testing pattern. Run ./gradlew :server:test; done means the old dependency and annotations are replaced, documentation is updated, and all tests pass.