Extract stroke commit callback helper

docs/modernization/debt.md

@@ -99,6 +99,12 @@ agent or engineer to remove them without reconstructing context from chat.
   leaving the method with only shell assembly and executor dispatch.
 - 2026-06-13: `LATER-003` was narrowed again. `Canvas::stroke_draw_mix()`
   now keeps only retained shell assembly and executor dispatch at the callsite.
+- 2026-06-13: `DEBT-0036` was narrowed again. `Canvas::stroke_commit()`
+  now routes the large retained callback bundle through a local helper, leaving
+  the callsite with sequence planning and helper invocation.
+- 2026-06-13: `DEBT-0036` was narrowed again. `Canvas::stroke_commit()`
+  now keeps the commit callback bundle in a local helper, leaving the callsite
+  with sequence planning and retained callback invocation only.
 - 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

@@ -644,6 +644,12 @@ Progress Notes:
 - 2026-06-13: `Canvas::stroke_draw_mix()` now keeps just the retained shell
   assembly and executor dispatch at the callsite; the framebuffer setup
   callbacks are isolated in the helper.
+- 2026-06-13: `Canvas::stroke_commit()` now routes the large retained callback
+  bundle through a local helper, leaving the callsite with sequence planning
+  and helper invocation.
+- 2026-06-13: `Canvas::stroke_commit()` now keeps the commit callback bundle
+  in a local helper, leaving the callsite with sequence planning and retained
+  callback invocation only.
 - 2026-06-13: `Canvas::stroke_draw_samples()` now reuses a retained destination
   texture dispatch helper for the live sample path; `Canvas` still owns the
   concrete face textures and callback execution.