Thin canvas draw seams and own grid worker

docs/modernization/debt.md

@@ -18,6 +18,22 @@ agent or engineer to remove them without reconstructing context from chat.
 
 ## Reductions
 
+- 2026-06-16: `DEBT-0036` was narrowed again. `NodeCanvas` smoothing-mask
+  overlay draw, smoothing-mask face pass, grid keepalive draw, heightmap draw,
+  and current-mode draw now route through
+  `execute_legacy_canvas_draw_merge_post_draw(...)` in
+  `src/legacy_canvas_draw_merge_services.h` instead of living inline in
+  `NodeCanvas::draw()`; broader canvas draw orchestration and retained GL
+  resource ownership remain.
+- 2026-06-16: `DEBT-0036` was narrowed again. The retained
+  `NodePanelGrid::bake_uvs()` worker now uses scoped `std::jthread` ownership
+  instead of a raw local `std::thread`; retained bake execution, progress-loop
+  polling, and grid rendering ownership remain.
+- 2026-06-16: `DEBT-0017` was narrowed again.
+  `LegacyPlatformServices::prepare_storage_paths()` now routes Apple storage
+  path setup through a local helper instead of reading `App::I` directly in
+  the method body; the retained Apple fallback adapter and broader
+  platform-to-app singleton reach remain.
 - 2026-06-16: `DEBT-0036` was narrowed again. `NodeStrokePreview` background
   preview execution now owns its worker as `std::jthread` with explicit stop,
   unblock, and join semantics instead of a raw `std::thread`; retained queue