# Handoff Report — worker_proto_server

## 1. Observation
- `scripts/compile_protos.py`: Previously compiled only into `client/src/proto/bundle.js`. Added `COCOS_PROTO_DIR = PROJECT_ROOT / "client" / "cocos" / "assets" / "scripts" / "proto"`, integrated `pbts` command to generate TypeScript declarations, and synchronized `bundle.js` (4,185,976 bytes) and `bundle.d.ts` (1,251,108 bytes) into `client/cocos/assets/scripts/proto/`. Execution of `python scripts/compile_protos.py` exited with code 0:
  ```
  [1/2] Compiling Protobuf for Python Server...
    OK Generated 17 Python proto modules in C:\Projects\FreeExile\server\proto
  [2/2] Compiling Protobuf for TypeScript Client...
    OK Generated TypeScript bundle & d.ts in C:\Projects\FreeExile\client\src\proto
    OK Synced Cocos Creator bundle & d.ts in C:\Projects\FreeExile\client\cocos\assets\scripts\proto
  All Protobuf bindings compiled successfully!
  ```
- `server/gateway/ws_gateway_bridge.py` (333 lines): Extended with 2-byte big-endian uint16 opcode table (`OPCODE_PACKET_ENVELOPE = 0x0001`, `OPCODE_PLAYER_MOVE_INPUT = 0x0002`, `OPCODE_ENTITY_STATE = 0x0003`, `OPCODE_ZONE_DATA = 0x0004`, `OPCODE_CAST_MARTIAL_SKILL = 0x0010`, `OPCODE_PHANTOM_EVASION = 0x0011`, `OPCODE_COMBAT_DAMAGE_EVENT = 0x0012`, `OPCODE_ENTER_ZONE_REQUEST = 0x0020`, `OPCODE_ZONE_PORTAL_DATA = 0x0021`, `OPCODE_CHAT_MESSAGE = 0x0030`, `OPCODE_AUTH_REQUEST = 0x0050`).
- Implemented `verify_zero_residual_momentum(entity_id, input_x, input_y)` in `server/gateway/ws_gateway_bridge.py`: when `abs(input_x) < 0.001 and abs(input_y) < 0.001`, velocity immediately snaps to `0.0, 0.0` and `anim_state = 0` (Idle), eliminating all residual momentum drift.
- Dual-mode framing handles binary frames (`isinstance(raw_msg, (bytes, bytearray))`) and preserves JSON diagnostics (`ping` -> `pong`, `skill_intent` -> `damage_event`, `auth_simulator` -> `auth_result`).
- `tests/unit/test_ws_protobuf_gateway.py` (273 lines): Implemented 8 comprehensive unit tests covering frame packing/unpacking, zero-residual momentum instant halt, roundtrip movement, combat skills, phantom evasion, zone data, portal data, chat messages, and JSON diagnostics.
- Ran `pytest tests/unit/test_ws_protobuf_gateway.py -v`:
  ```
  tests/unit/test_ws_protobuf_gateway.py::TestWsProtobufGateway::test_binary_frame_encode_decode PASSED [ 12%]
  tests/unit/test_ws_protobuf_gateway.py::TestWsProtobufGateway::test_websocket_combat_skill_and_evasion_roundtrip PASSED [ 25%]
  tests/unit/test_ws_protobuf_gateway.py::TestWsProtobufGateway::test_websocket_envelope_portal_auth_roundtrip PASSED [ 37%]
  tests/unit/test_ws_protobuf_gateway.py::TestWsProtobufGateway::test_websocket_legacy_json_diagnostics PASSED [ 50%]
  tests/unit/test_ws_protobuf_gateway.py::TestWsProtobufGateway::test_websocket_player_move_input_roundtrip PASSED [ 62%]
  tests/unit/test_ws_protobuf_gateway.py::TestWsProtobufGateway::test_websocket_zero_residual_momentum_diagonal PASSED [ 75%]
  tests/unit/test_ws_protobuf_gateway.py::TestWsProtobufGateway::test_websocket_zone_and_chat_roundtrip PASSED [ 87%]
  tests/unit/test_ws_protobuf_gateway.py::TestWsProtobufGateway::test_zero_residual_momentum_instant_halt PASSED [100%]
  ======================== 8 passed, 2 warnings in 0.95s ========================
  ```
- Ran `python tools/lint/check_code_and_doc_hygiene.py`: Output confirmed 0 hard cap violations. Modified logic files adhere to the strict soft cap `<= 350` lines:
  * `server/gateway/ws_gateway_bridge.py`: 333 lines (<= 350)
  * `tests/unit/test_ws_protobuf_gateway.py`: 273 lines (<= 350)
  * `scripts/compile_protos.py`: 114 lines (<= 350)

## 2. Logic Chain
1. In `scripts/compile_protos.py`, extending `compile_typescript_protos` to invoke `pbts` and synchronize artifacts to `client/cocos/assets/scripts/proto/` directly satisfies Milestone M3 Requirement 1 and ensures the Cocos Creator TypeScript client has full static type safety across all 17 schema packages.
2. In `server/gateway/ws_gateway_bridge.py`, inspecting frame type (`bytes` vs `str`) and using a 2-byte big-endian uint16 opcode header enables zero-overhead demuxing of high-frequency binary Protobuf packets while keeping legacy JSON connectivity intact.
3. The `verify_zero_residual_momentum` routine enforces that when input coordinates drop below epsilon (`< 0.001`), server-authoritative velocity is clamped to exactly `0.0, 0.0` in frame 0, fulfilling the zero-residual momentum requirement specified in both the original request and the survey blueprint.
4. Independent execution of 8 unit tests in `tests/unit/test_ws_protobuf_gateway.py` proves that binary frames over real WebSocket connections (`ws://127.0.0.1:18080`) correctly roundtrip, validate momentum, and return opcode-prefixed Protobuf responses.

## 3. Caveats
- No client-side Cocos scripts outside of `client/cocos/assets/scripts/proto/` were modified, respecting exclusive ownership boundaries.
- Live port 8080 was tested via unit test on dedicated port 18080 to prevent interfering with any background daemon on port 8080.
- All 17 `.proto` files are bundled; any future addition of `.proto` files will automatically be included by re-running `python scripts/compile_protos.py`.

## 4. Conclusion
Milestone M3 is completely implemented and verified:
1. Cocos Protobuf bundle and typings are generated and synced at `client/cocos/assets/scripts/proto/bundle.js` and `bundle.d.ts`.
2. `server/gateway/ws_gateway_bridge.py` supports dual-mode framing with the full 2-byte big-endian opcode dispatch table and authoritative zero-residual momentum verification.
3. All 8 unit tests pass with zero errors, and all files comply with code hygiene limits (<= 350 lines).

## 5. Verification Method
- **Run Protobuf Compiler**:
  ```bash
  python scripts/compile_protos.py
  ```
  Expected: Exits with code 0; confirms sync to `client/cocos/assets/scripts/proto/`.
- **Run Unit Tests**:
  ```bash
  pytest tests/unit/test_ws_protobuf_gateway.py -v
  ```
  Expected: All 8 tests pass.
- **Run Hygiene Check**:
  ```bash
  python tools/lint/check_code_and_doc_hygiene.py
  ```
  Expected: Zero hard cap violations; modified files <= 350 lines.
- **Inspect Files**:
  * `client/cocos/assets/scripts/proto/bundle.js`
  * `client/cocos/assets/scripts/proto/bundle.d.ts`
  * `server/gateway/ws_gateway_bridge.py`
  * `tests/unit/test_ws_protobuf_gateway.py`