# WBV2-P28-004: implement_render_capability_workbench

- task: WBV2-P28-004
- parent: WBV2-P28-003
- status: in_progress
- gap: RENDER.CAPABILITY_WORKBENCH
- ownerFamily: RENDER
- targetImplementationClass: SOURCE_BACKED

## 目标

Expose shader, WebGPU, post-process and compositor capability routes.

## 输入与范围

- Focused protocol: `web/protocol/web-engine.ts`
- Focused capability registry: `web/protocol/web-engine-capabilities.ts`
- Focused Main source: `blender-5.2.0/source/blender/web_engine/web_engine_main_state.cpp`
- Implementation entrypoint: `node tools/web/generate-wbv2-implementation-continuation-slice.mjs --task WBV2-P28-004 --write`

## 验收

- real source or WebEngine Main implementation is present and connected
- workbench route uses typed protocol without a duplicate shim
- malformed, unsupported, hash-drift or false-completion input fails closed
- implementation smoke is reproducible; Chromium receipts, undo/redo, save/reopen and deterministic verification remain deferred
- `node tools/web/check-task-context.mjs --task WBV2-P28-004 --write`

## 交付与回滚

- Reports: `tests/golden/WBV2-P28-004/`
- Status: `docs/status/WBV2-P28-004.md`
- Manifest: `tests/golden/WBV2-P28-004/manifest.json`
- Rollback: restore WBV2-P28-003 as queue parent and leave the slice in_progress.