[oglassdev]

Summary

Lets apps bring their own session isolation instead of being bound to the multistom fork.

• jvm/runtime gains engine-neutral primitives:
  • SessionHandler — the app decides what a session is (create, finish, optional method).
  • SessionControl — reports ready() (returns whether it took effect) / fail() / ended() back to core.
  • SessionMethod — one session method call; handlers call start() right before running effects, which re-checks cancellation, the deadline and the player's delivery.
  • Delivery — a delivered player: arrived(), left() (stops methods, keeps the fence), release(), move(destination), operationId(action).
  • ChunkSessions — the ledger behind ChunkProcess.host(handler): applies jvm/<host> entries, admits players by their chunk:delivery capability, enforces the creation deadline, fences generations, and reports JvmReports.
  • ChunkProcess adds public host, tick, bind(port, protocol) and playerAddress().
• jvm/minestom (new, artifact com.chunkzero.chunk:minestom): ChunkLogin for upstream net.minestom:minestom. It answers the login request, admits only prepared deliveries with the gateway-authenticated profile, and releases each delivery after the app's leave handler once the connection closes. Spawning, arrival and isolation stay with the app (shared instances, several per session, or max_sessions = 1).
• jvm/multistom (renamed from jvm/runtime-minestom; runtime-minestom-kotlin is now multistom-kotlin) is rebuilt on top: SessionManager implements SessionHandler, and ProcessService / SessionMethodService are gone.

Behavior changes

• The multistom runtime moved from com.chunkzero.chunk.runtime to com.chunkzero.chunk.multistom (.assets, .bootstrap, .event, .internal); engine-neutral classes stay in com.chunkzero.chunk.runtime. Generated code (Gradle plugin registries, chunk-build Java codegen and release analysis) targets the new names, so apps need the matching chunk CLI. SessionControl.isReady() and ChunkProcess.app() are now public; ManagedSession.getPhase() is gone.

• Artifacts renamed: runtime-minestom → multistom, runtime-minestom-kotlin → multistom-kotlin. The version catalog calls the fork libs.multistom and upstream libs.minestom. minestom and multistom are independent; neither depends on the other.

• ATTACHED is reported at admission rather than when the player reaches PLAY.

• A session method that its handler completes without calling start() reports CANCELLED; one that fails before starting (e.g. undeclared) reports FAILED.

• ChunkMinestom's tick notices disconnects (gameplay.flush()) before running queued tick tasks.

• runtime-minestom-kotlin and runtime tests now build sessions through ChunkSessions.detached(...).

• jvm/runtime exposes backend-client as api.

Known limitations

• The Gradle plugin still always adds multistom (the fork) and generates @SessionType registrations, so a chunk project can't opt into upstream Minestom yet. That needs a follow-up.
• No finish deadline: a session stays ENDING until the handler calls ended(), same as before.

Validation

• ./gradlew :jvm:runtime:test :jvm:multistom:test :jvm:multistom-kotlin:test :jvm:minestom:test, jvm/gradle-plugin tests
• examples/local CoinCommandTest
• just fmt
• cargo test -p chunk-build (release, codegen); examples/{local,arena,load} testClasses
• 9 rounds of GPT-6.1 Sol review; the final round was clean.

🤖 Generated with Claude Code