Trim main task queue, recording label, and canvas draw callbacks

docs/modernization/debt.md

@@ -18,6 +18,22 @@ agent or engineer to remove them without reconstructing context from chat.
 
 ## Reductions
 
+- 2026-06-16: `DEBT-0003` was narrowed again. `main.cpp` main-thread queued
+  task state now lives behind a narrow retained helper instead of
+  `RetainedState.main_tasklist` / `main_task_mutex` directly; broader Win32
+  bootstrap/runtime ownership remains.
+- 2026-06-16: `DEBT-0037` was narrowed again. `App::update_rec_frames()` in
+  `src/app.cpp` now delegates recording label refresh through
+  `update_legacy_recording_frame_label(...)` in
+  `src/legacy_recording_services.cpp` instead of building the label directly;
+  retained recording label lookup, encoder-state reads, and MP4 execution
+  remain.
+- 2026-06-16: `DEBT-0036` was narrowed again. `NodeCanvas` non-`draw_merged`
+  per-frame layer draw callback setup now routes through
+  `make_legacy_canvas_draw_merge_layer_frame_draw(...)` in
+  `src/legacy_canvas_draw_merge_services.h` instead of keeping that callback
+  body inline in `NodeCanvas::draw()`; broader canvas draw orchestration and
+  retained GL resource ownership remain.
 - 2026-06-16: `DEBT-0003` was narrowed again. The Win32 async GL/context lock
   state now lives in `src/platform_windows/windows_platform_services.cpp`
   instead of `src/main.cpp` retained state, and `main.cpp` only seeds the