Thin canvas modes, node execution, and canvas draw shell

docs/modernization/tasks.md

@@ -108,6 +108,11 @@ Current slice:
   `src/legacy_canvas_projection_services.*` instead of staying inline in
   `src/canvas.cpp`, which trims another coherent non-UI state/query pocket
   from the live canvas shell.
+- Shared canvas-mode GL wrappers plus the `CanvasModeBasicCamera` and
+  `CanvasModeCamera` input handlers now also live in
+  `src/legacy_canvas_mode_helpers.*` instead of staying inline in
+  `src/canvas_modes.cpp`, which trims another coherent retained canvas-view
+  interaction pocket from the broader canvas/render hotspot family.
 
 Write scope:
 - `src/canvas.cpp`
@@ -252,6 +257,12 @@ Current slice:
   `execute_legacy_canvas_draw_node_canvas_unmerged_pass(...)`, which
   materially shortens the live `NodeCanvas::draw()` body even though the file
   itself is still large.
+- `NodeCanvas::draw()` unmerged-pass blend-gate query, layer-orientation
+  assembly, and callback wiring into
+  `execute_legacy_canvas_draw_node_canvas_unmerged_pass(...)` now also route
+  through `execute_node_canvas_draw_unmerged_pass(...)`, which trims another
+  coherent unmerged draw-orchestration block from the live node even though
+  the file size remains roughly flat.
 
 Write scope:
 - `src/node_stroke_preview.cpp`
@@ -673,6 +684,11 @@ Current slice:
   That trims another coherent generic node-instantiation pocket and makes the
   remaining scene-graph load path easier to isolate, even though ownership has
   not yet moved into `pp_ui_core`.
+- The generic per-frame node execution/traversal family for
+  `restore_context`, `clear_context`, `update`, `update_internal`, and `tick`
+  now also lives in `src/legacy_ui_node_execution.cpp` instead of staying
+  inline in `src/node.cpp`, which materially thins the base scene-graph file
+  without changing its public surface.
 
 Write scope:
 - `src/node.cpp`