Add Chromium-only Blender WebEngine parity work

docs/status/W-076.md

@@ -0,0 +1,46 @@
+# W-076 Status
+
+status: in_progress  
+task: 属性、UV 和蒙皮安全简化
+
+`SimplifyProfile` now requires an explicit attribute policy after parsing and
+defines `SkinSimplifyPolicy` limits for influences, weights, position error and
+shape keys. The native command currently implements this partial protection
+matrix:
+
+- normals are recomputed from the evaluated triangle topology;
+- BMFace material indices and material slot IDs are retained;
+- existing UV and float-color corner values are transferred to output corners
+  using a deterministic closest-source-triangle barycentric projection;
+- `DROP` is the only policy that removes these arrays intentionally;
+- Collapse validates and accepts open/non-manifold Mesh-to-BMesh topology;
+- the native reader exports Mesh `MDeformVert` CustomData as fixed four-slot
+  `SkinWeightsIR` arrays, carries Mesh vertex-group names, and exports
+  non-Basis `KeyBlock` positions as `ShapeKeyIR`; the local
+  `rigged_shape_scene.blend` fixture validates both on a real `.blend` file;
+- a skinned or shape-key mesh requires explicit `skinPolicy`; omitting it is a
+  structured `NOT_IMPLEMENTED` failure rather than silent attribute loss.
+
+Native smoke and browser Worker E2E verify normal, UV, corner and material
+buffer sizes on the closed cube fixture. The WebEngine protocol validates
+`SkinWeightsIR` and `ShapeKeyIR`. After BMesh produces the authoritative
+topology, native code projects each output vertex onto the closest source
+triangle, merges and normalizes its joint influences, and reconstructs every
+shape-key position with the same barycentric weights. `maxInfluences`,
+`minWeight` and `maxPositionError` are enforced before committing the new
+SceneIR. Native smoke and Worker E2E verify output vertex counts, normalized
+weights, stable joint IDs, bind matrices and shape-key array lengths.
+`shapeKeys: REJECT` still returns `SHAPE_KEYS_REJECTED` before native work.
+
+The reader now exports `ArmatureIR` bones with parent IDs, Blender `Bone.arm_mat`
+rest matrices and matching `PoseChannel.pose_mat` matrices. A mesh Armature
+modifier resolves its armature object, remaps vertex-group bone names to stable
+joint IDs, and records the mesh object TRS as its non-identity bind matrix. The
+generated rig fixture verifies all fields against local Blender data. This is
+sufficient for GLB inverse-bind generation and the current triangle-bridge
+remapping path.
+
+UV seam and sharp-edge error metrics, tangent regeneration, native
+vertex-group name selection in profiles, Armature deformation comparison,
+seam/sharp constraints and Blender-evaluated shape-key error comparison remain
+required before this task can be marked done.