Promote stroke draw sampler dispatch task

docs/modernization/tasks.md

@@ -607,6 +607,33 @@ ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_composito
 | --- | --- | --- | --- | --- |
 | 2026-06-13 | STR-020 | +1 renderer boundary and OpenGL parity | `ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_compositor|pp_paint_renderer_stroke_execution" --output-on-failure` | `87e6c111` |
 
+### STR-021 - Extract Stroke Draw Live Pass Sampler Dispatch
+
+Status: Ready
+Score: +1 renderer boundary and OpenGL parity
+Debt: `DEBT-0036`
+Scope: `src/canvas.cpp`, `src/legacy_canvas_stroke_execution_services.h`, `tests/paint_renderer/compositor_tests.cpp`
+
+Goal:
+
+Move the inline `Canvas::stroke_draw()` live-pass sampler dispatch bundle into
+a retained helper so the callsite keeps only branch selection plus concrete
+sampler wiring.
+
+Done Checks:
+
+- `Canvas::stroke_draw()` no longer builds the live-pass sampler dispatch
+  bundle inline.
+- Regression coverage proves the extracted helper preserves sampler callback
+  order.
+- `docs/modernization/debt.md` records the reduced live-pass sampler surface.
+
+Validation:
+
+```powershell
+ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_compositor|pp_paint_renderer_stroke_execution" --output-on-failure
+```
+
 Progress Notes:
 
 - 2026-06-13: `NodeStrokePreview::draw_stroke_immediate()` now routes final