Record stroke commit face binding boundary

docs/modernization/debt.md

@@ -112,6 +112,9 @@ agent or engineer to remove them without reconstructing context from chat.
   now routes the commit-input texture role switch through a retained service
   helper, leaving the callsite with sequence planning and concrete face
   bindings only.
+- 2026-06-13: `DEBT-0036` was narrowed again. `Canvas::stroke_commit()`
+  now routes the face-indexed commit-input binding wrapper through the retained
+  service boundary, leaving `Canvas` with only concrete face bindings.
 - 2026-06-13: `DEBT-0036` was narrowed again. `NodeStrokePreview::draw_stroke_immediate()`
   now routes final composite execution and preview copy-back through a retained
   local wrapper, leaving the call site with only sequence wiring.

docs/modernization/tasks.md

@@ -1188,6 +1188,38 @@ Completed Task Log:
 | --- | --- | ---: | --- | --- |
 | 2026-06-13 | STR-009 | +2 renderer boundary and OpenGL parity | `ctest --preset desktop-fast --build-config Debug -R "retained_stroke_commit_callback_builder_preserves_order|retained_stroke_commit_runner_preserves_per_face_step_order" --output-on-failure`; `& 'C:\Program Files\Microsoft Visual Studio\18\Community\MSBuild\Current Bin\MSBuild.exe' out\build\windows-msvc-default\tests\pp_paint_renderer_compositor_tests.vcxproj /p:Configuration=Debug /p:Platform=x64` | `e7813c2f` |
 
+### STR-013 - Extract Stroke Commit Face Input Binding
+
+Status: Done
+Score: +1 renderer boundary and OpenGL parity
+Debt: `DEBT-0036`
+Scope: `src/legacy_canvas_stroke_commit_services.h`, `tests/paint_renderer/compositor_tests.cpp`
+
+Goal:
+
+Move the face-indexed commit-input binding wrapper behind the retained stroke
+commit service boundary so `Canvas::stroke_commit()` only supplies concrete
+face bindings.
+
+Done Checks:
+
+- `Canvas::stroke_commit()` uses the retained face-input binding helper.
+- Regression coverage proves the face-input helper forwards the sequence slots.
+- `docs/modernization/debt.md` records the reduced stroke-commit face-binding
+  surface.
+
+Validation:
+
+```powershell
+ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_stroke_execution|pp_paint_renderer_compositor" --output-on-failure
+```
+
+Completed Task Log:
+
+| Date | Task | Score | Validation | Commit |
+| --- | --- | ---: | --- | --- |
+| 2026-06-13 | STR-013 | +1 renderer boundary and OpenGL parity | `ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_stroke_execution|pp_paint_renderer_compositor" --output-on-failure` | `6220f333` |
+
 ### STR-011 - Extract Preview Main Pass Orchestration
 
 Status: Done