Thin node loader, Win32 wrappers, and canvas mode shells

docs/modernization/tasks.md

@@ -391,6 +391,10 @@ Current slice:
   render-target validation, viewport/clear-color save-restore, and immediate
   runtime request assembly out of the live node file and leaves
   `src/node_stroke_preview.cpp` at 160 lines.
+- `CanvasModeGrid` plus `ActionModeGrid` undo/redo now also live in
+  `src/legacy_canvas_mode_helpers.cpp` instead of staying inline in
+  `src/canvas_modes.cpp`, which leaves the live canvas-modes file as a
+  minimal shell.
 - `NodeCanvas::init()` plus the remaining `NodeCanvas::draw()` outer shell now
   also live in `src/legacy_node_canvas_draw_services.*` instead of staying
   inline in `src/node_canvas.cpp`, which materially reduces the live node to a
@@ -908,6 +912,10 @@ Current slice:
   base clone plumbing now also lives in `src/legacy_ui_node_lifecycle.*`
   instead of staying inline in `src/node.cpp`, which materially thins another
   coherent generic scene-graph shell without changing the public surface.
+- `Node::load_internal(...)` now also routes through
+  `load_legacy_ui_node(...)` in `src/legacy_ui_node_loader.*`, which moves the
+  init/attribute-parse/create/child-load/loaded shell out of `src/node.cpp`
+  and leaves the remaining live node file thinner.
 
 Write scope:
 - `src/node.cpp`
@@ -1090,6 +1098,12 @@ Current slice:
   directly in those method bodies
 - retained Apple callback injection and broader `platform_legacy` singleton
   reach are still open
+- The remaining Win32 shell wrappers for close, async lock/swap,
+  stylus/FPS updates, VR start/stop, window-state save, and the
+  window-handle accessor now live in
+  `src/platform_windows/windows_platform_services.cpp` instead of
+  `src/main.cpp`, which leaves the live entry file as a thinner
+  startup/runtime dispatcher.
 
 Write scope:
 - `src/platform_apple/*`