# WBV2-P1121-000: paint stroke module

- task: `WBV2-P1121-000`
- parent: `WBV2-P1120-000`
- status: `in_progress`
- gap: `workflow:module_paint_stroke`
- ownerFamily: `SCULPT`
- targetImplementationClass: `LOCAL_BOUNDED`

## 目标

按功能模块验证 paint pointer session、GPU depth visibility 和 PBVH capability gate。

## 输入与范围

- Blender Main/API: `blender-5.2.0/source/blender/web_engine/web_engine_main_state.cpp`, `blender-5.2.0/source/blender/web_engine/web_engine_main_state.h`, `blender-5.2.0/source/blender/web_engine/web_engine_api.cpp`
- Protocol: `web/protocol/web-engine.ts`, `web/protocol/sculpt.ts`, `web/protocol/paint.ts`, `web/protocol/paint-stroke-session.ts`, `web/protocol/paint-depth-visibility.ts`, `web/protocol/paint-pbvh-capability.ts`
- Runtime: `web/app/src/workers/web-engine.worker.ts`, `web/app/src/three-adapter/paint-depth-visibility.ts`, `web/app/src/three-adapter/viewport.ts`, `web/app/src/three-adapter/offscreen-viewport.ts`, `web/app/src/app/App.tsx`

## 验收

```bash
npm --prefix web run test:paint-stroke-session
npm --prefix web run test:paint-depth-visibility
npm --prefix web run test:paint-pbvh-capability
npm --prefix web run typecheck
```

必须记录 pointer chunks/undo 正例、stale/forged/budget/PBVH-unavailable 负例、cancel cleanup、worker restart、main/offscreen GPU 和 Chromium。PBVH 缺 entrypoint 保持 BLOCKED，不推导 sculpt brush parity。

## 交付与回滚

- Receipt: `tests/golden/WBV2-P1121-000/module-receipt.json`
- Manifest: `tests/golden/WBV2-P1121-000/manifest.json`
- Status: `docs/status/WBV2-P1121-000.md`
- 回滚：恢复 P1120 manifest 为 queue parent。