## 7. Agent Log
*(Append updates below)*
- @product_owner: Created task.
- @scrum_master: Moved to design phase. Assigned to @architect.
- @architect: Design complete. Analyzed chunk packet wire format (SetChunk packetId=131, SetChunkHeightmap packetId=132, UnloadChunk packetId=135) from decompilation. Designed zero-allocation packet writers using IBufferWriter<byte>. Specified chunk data structures (ChunkPosition, ChunkSectionData, ChunkColumnData, StaticWorld). For Phase 1 MVP, designed FlatWorldGenerator to create simple in-memory flat world (no external files needed). Integration point: send chunks immediately on entering Setup phase. See docs/design/STORY-009_static-world-chunk-loading.md for full spec. Ready for CAB review.
- @manager: Created design spec docs/design/STORY-009_static-world-chunk-loading.md with wire format details.
- @cab: CHANGES REQUESTED - The `WriteSetChunk` code sample in the design spec conflates packet payload with frame header. The Java `serialize()` method writes payload only (starts at nullBits, byte 0), not the frame header. The design must clarify: (1) `WorldPacketWriter` methods produce **uncompressed payload only** (starting with nullBits at offset 0, not offset 8), (2) The framing layer (`LengthPrefixedFramer`) and compression layer (`PacketCompression`) handle header/compression separately. Fix the code sample to show payload-only writing (remove span[0..8] frame header from the example), then resubmit for review.
- @manager: Fixed design spec - WorldPacketWriter now produces payload-only (nullBits at offset 0). Added usage pattern showing integration with ProtocolWriter.WriteFrame(). Resubmitting for CAB review.
- @cab: Design approved. Verified: (1) WriteSetChunkPayload starts at offset 0 with nullBits, no frame header; (2) Usage pattern correctly delegates framing to ProtocolWriter.WriteFrame(); (3) Span<byte> + int return type is clean zero-alloc pattern; (4) Scope unchanged (FlatWorldGenerator for Phase 1 MVP). Ready for implementation.
- @scrum_master: Assigned to @dev_senior for implementation, @dev_junior for testing. Branch: feat/story-009-static-world-chunks. Moved to implementation phase.
- @dev_senior: Implementation complete. Created all data structures (ChunkPosition, ChunkSectionData, ChunkColumnData, StaticWorld), FlatWorldGenerator for in-memory flat world generation, WorldPacketWriter with zero-allocation packet serialization. Registered packets 131/132/135 in PacketRegistry. Updated DI to register StaticWorld and WorldOptions. Chunks are sent when client transitions to Setup phase in ProtocolConnectionHandler. Existing tests updated to accommodate new DI parameters. Build succeeds. Test results: 22/24 passing (2 failures are expected due to chunks now being sent before keepalive ping). Commit eb18ee42 pushed to branch feat/story-009-static-world-chunks. Ready for code review.
- @cab: Code approved. Review findings: (1) Protocol correctness verified - SetChunk/SetChunkHeightmap/UnloadChunk match wire format spec with LE integers via BinaryPrimitives; (2) Zero-allocation in hot paths - SendInitialChunksAsync uses ArrayPool.Shared, WorldPacketWriter uses Span<byte>; (3) No banned types (BinaryReader/BinaryWriter); (4) new byte[] in FlatWorldGenerator is startup-only (pre-serialized to StaticWorld singleton), acceptable for Phase 1; (5) Scope matches Phase 1 spec (flat world, no file I/O). Test failures (2/24) are expected behavior changes - tests need updating to consume chunk packets before asserting on keepalive. **ACTION for @dev_junior:** Update `Setup_phase_does_not_immediately_disconnect_on_unknown_packet` and `Sends_keepalive_ping_after_setup_without_more_inbound` to drain chunk packets (131/132) after login response before their existing assertions. Once tests are fixed, merge to main.
- @dev_junior: Test fixes complete. Both failing tests now properly drain chunk packets (131/132) sent on Setup phase entry before checking keepalive ping. Added loop in each test to consume packets until packet ID 2 (keepalive) is received. All 24 tests now pass (24/24). Commit 44553eb9 "test: Drain chunk packets before checking keepalive ping (STORY-009)" pushed to feat/story-009-static-world-chunks. Ready to move to code review.
- @cab: **CODE APPROVED.** Re-review findings:
  1. **Tests verified:** All 24 tests pass (24/24).
  2. **Test fix appropriate:** Drain loop correctly consumes chunk packets (131/132) before asserting keepalive (packet ID 2). Pattern is sound - loop until target packet ID is reached.
  3. **Zero-allocation in hot paths:** `SendInitialChunksAsync` uses `ArrayPool<byte>.Shared.Rent/Return`; `WorldPacketWriter` uses `Span<byte>` with `BinaryPrimitives` for LE encoding.
  4. **No banned types:** No `BinaryReader`/`BinaryWriter` in codebase.
  5. **`new byte[]` in FlatWorldGenerator:** Startup-only allocation (pre-serialized to singleton), acceptable for Phase 1 MVP.
  6. **Data structures correct:** `ChunkPosition` is `readonly struct`, `ChunkSectionData` uses `required` properties.
  7. **Scope matches Phase 1:** Flat world generator, no file I/O, no generation, no persistence.
  **ACTION for @manager:** Merge `feat/story-009-static-world-chunks` to `main` and push. Move card to `06_done`.