Narrow retained canvas stroke execution helpers

docs/modernization/debt.md

@@ -1,7 +1,7 @@
 # Modernization Debt Log
 
 Status: live
-Last updated: 2026-06-06
+Last updated: 2026-06-13
 
 Every shortcut, temporary adapter, retained vendored dependency, skipped
 platform gate, compatibility shim, or incomplete automation path must be
@@ -18,6 +18,16 @@ agent or engineer to remove them without reconstructing context from chat.
 
 ## Recent Reductions
 
+- 2026-06-13: DEBT-0036 was narrowed again. `Canvas::stroke_commit` retained
+  commit input texture/sampler binding, erase/composite draw dispatch,
+  committed-copy-to-dilate-source, and dilate draw now route through
+  `legacy_canvas_stroke_commit_services.h`; Canvas still owns history
+  readback, `ActionStroke` population, layer dirty-box mutation, and retained
+  RTT/framebuffer ownership.
+- 2026-06-13: DEBT-0036 was narrowed again. `Canvas::stroke_draw` pad-pass
+  dirty-face iteration, pad-region planning, and NDC quad assembly now route
+  through a retained stroke execution helper callback boundary; Canvas still
+  owns framebuffer copies, brush-shape uploads, and draw execution.
 - 2026-06-13: DEBT-0036 was narrowed again. `Canvas::stroke_draw` current and
   dual stroke frame-face traversal now routes through the retained stroke
   execution helper; framebuffer binding, shader uniform timing, dirty-box

docs/modernization/roadmap.md

@@ -1,7 +1,7 @@
 # PanoPainter Modernization Roadmap
 
 Status: live
-Last updated: 2026-06-12
+Last updated: 2026-06-13
 
 This is the living roadmap for modernizing PanoPainter into independently
 testable C++23 components while retaining all existing functionality. Keep this
@@ -3083,6 +3083,15 @@ Results:
   execution helper wrapping `pp_paint_renderer`, while pad color selection,
   dirty-face iteration, framebuffer copies, quad upload, and draw execution
   remain retained.
+- `Canvas::stroke_draw` pad-pass dirty-face iteration, pad-region planning, and
+  NDC quad assembly now share a retained stroke execution helper callback
+  boundary, while Canvas still owns framebuffer copies, brush-shape uploads,
+  and draw execution.
+- `Canvas::stroke_commit` retained commit input texture/sampler binding,
+  erase/composite draw dispatch, committed-copy to the dilate scratch texture,
+  and dilate draw now share `legacy_canvas_stroke_commit_services.h`; history
+  readback, `ActionStroke` population, layer dirty-box mutation, and retained
+  RTT/framebuffer ownership remain in the legacy Canvas path.
 - `Canvas::stroke_draw_compute` frame planning now shares the retained stroke
   execution helper for brush-quad construction, mixer feedback bounds, 2D/3D
   projection selection intent, and frame assembly, while legacy projection

docs/modernization/tasks.md

@@ -1,7 +1,7 @@
 # Modernization Task Tracker
 
 Status: live
-Last updated: 2026-06-12
+Last updated: 2026-06-13
 
 This file turns the modernization roadmap into small, measurable work items.
 The roadmap explains direction, the debt log explains why shortcuts remain, and
@@ -509,6 +509,11 @@ Done Checks:
 
 Progress Notes:
 
+- 2026-06-13: `Canvas::stroke_commit` now routes retained commit input
+  texture/sampler binding, erase/composite draw dispatch, committed-copy, and
+  dilate draw through `legacy_canvas_stroke_commit_services.h`; history
+  readback, `ActionStroke` population, and layer dirty-box mutation remain
+  local to Canvas.
 - 2026-06-13: `pp_paint_renderer` owns tested Canvas stroke commit sequencing
   and commit texture slot intent. Next slice should wire
   `legacy_canvas_stroke_commit_services.h` into `Canvas::stroke_commit` while