[oglassdev]

Stacked on #334.

Summary

Generated code and the Gradle plugin no longer target any engine types, so the session, method and component machinery works for any host, not just multistom.

• Contracts in jvm/runtime (com.chunkzero.chunk.runtime): SessionProvider<S>, ConfiguredSessionProvider<C, S>, SessionCreation<C>, SessionMethodBinding<S, A, R>, SessionMethodProvider, ComponentBinding, ComponentProvider.
• Engine-neutral registries: SessionRegistry (loads providers, decodes configs), SessionMethodRegistry and ComponentRegistry. An app on upstream Minestom can use them from its own SessionHandler.
• @Component.Supplied: hosts mark the types they hand to session-scoped component factories. The plugin reads the marker from bytecode instead of hard-coding multistom's SessionScope; BackendSession stays built in.
• multistom uses the runtime contracts, supplies SessionScope and BackendSession, and fails a session's creation if its provider doesn't create a multistom Session.
• Codegen: configured provider interfaces are generic over the session type. Apps write implements ArenaSessionProviders.Koth<ArenaSession>, and plain providers implement SessionProvider<LobbySession>. Session method adapters are typed (new SessionMethodBinding<>(REF, ArenaSession.class, (session, args) -> session.status(args))).
• Release analysis and check-consumers.py read the com.chunkzero.chunk.runtime.* service files.

Breaking changes

• Providers declare their session type: SessionProvider<S> / XSessionProviders.Y<S>.
• Contract imports move from com.chunkzero.chunk.multistom to com.chunkzero.chunk.runtime.
• Apps must be rebuilt with the matching chunk CLI and Gradle plugin, since the service file names changed.

Notes

• The plugin no longer checks at build time that a session is a multistom Session. multistom checks it when creating each session.
• The plugin still adds multistom; the next PR in the stack reworks that.

Validation

• ./gradlew :jvm:runtime:test :jvm:multistom:test :jvm:multistom-kotlin:test :jvm:minestom:test
• jvm/gradle-plugin tests
• cargo test -p chunk-build (codegen, release)
• examples/{local,arena,load} testClasses with a rebuilt CLI, plus CoinCommandTest
• just fmt-check

🤖 Generated with Claude Code