feat(blender): extension set live in the GUI; MCP acceptance 9/9, probe made safe-mode compliant

stacks/blender/README.md

@@ -230,4 +230,25 @@ z = 0, area 399.999982 mm² against 400. Extruded 2 mm, it gave a valid 799.9999
 real NURBS surface reaches the kernel, not triangles, and millimetres hold across the hop. That is
 one run of a flat bilinear patch; curved and trimmed patches are untested.
 
-**MCP (GUI) path:** pending the stack deploy that mounts the repo and hook into the GUI container.
+**MCP (GUI) path, 2026-09-28 1506 (after Prime ran the deploy):** the hook log read
+`enabled 8/8`, `hardened: surfacepsycho ... literal_eval`, `online access: False`. Through
+`scripts/blender-mcp` → `execute_blender_code` under safe mode, the probe passed **9 of 9**,
+including CAD Sketcher (a sketch on the XY origin plane, then a full solve), because the GUI has
+the workspace tool that `-b` lacks. The eval patch held under MCP: the code payload was refused
+(`ValueError: malformed node`) and the literal `{3, 5}` was accepted.
+- **CAD Sketcher sketch, re-solved headless:** the MCP-made sketch was saved
+  (`cad-sketch-mcp.blend`), then `blender-run --cpu --extensions` opened it and
+  `view3d.slvs_solve(all=True)` returned FINISHED. Authoring is in the GUI; re-solving works in batch.
+- **Not solved yet:** drawing CAD Sketcher geometry from code. `slvs_add_rectangle` with
+  `p1_fallback`/`p2_fallback` and `wait_for_input=False` raised
+  `'NoneType' object has no attribute 'co'`. Its drawing ops are stateful and expect point picks,
+  and its Python entity API is out of reach under safe mode. Sketches work; agent-drawn profiles
+  need more work.
+- **Not confirmed:** MeasureIt overlays in `get_viewport_screenshot`. The segment was created and
+  `measureit.runopengl` returned FINISHED, but two screenshots (a top view with a 20 mm edge
+  dimension) showed no dimension.
+- `blender-run --extensions` (the real wrapper, `--cpu`) ran the same probe at 8 of 9, the one
+  miss being CAD Sketcher for the headless reason above.
+
+Safe-mode note for probe authors: safe mode refuses calling a function held in a variable and
+any dunder attribute (`type(ex).__name__`). The probe calls each test by name and uses `repr(ex)`.