Route stroke pad planning through helper

docs/modernization/roadmap.md

@@ -3079,6 +3079,10 @@ Results:
   compositor coverage now includes malformed retained commit plans plus
   all-input stroke-preview composite planning. Live stroke rasterization,
   callback execution, texture binding, and history mutation remain retained.
+- `Canvas::stroke_draw` pad-region planning now shares the retained stroke
+  execution helper wrapping `pp_paint_renderer`, while pad color selection,
+  dirty-face iteration, framebuffer copies, quad upload, and draw execution
+  remain retained.
 - Remaining simple color, hue, color-quad, grid heightmap, and pen/line
   preview shader setup in UI nodes and canvas modes now shares retained helper
   surfaces, while geometry, texture/sampler binding, blend/depth state,