Extract layout bootstrap and thin NodeCanvas startup shells

docs/modernization/tasks.md

@@ -235,6 +235,13 @@ Current slice:
   `execute_legacy_canvas_draw_unmerged_node_canvas_pass(...)`, which removes
   another coherent outer-shell block even though the broader node draw loop
   still lives in `src/node_canvas.cpp`.
+- `NodeCanvas::draw()` setup, merged-pass shell, and unmerged-pass shell now
+  also route through `prepare_legacy_node_canvas_draw_setup(...)`,
+  `execute_legacy_canvas_draw_node_canvas_shell(...)`,
+  `execute_legacy_canvas_draw_merged_pass(...)`, and
+  `execute_legacy_canvas_draw_node_canvas_unmerged_pass(...)`, which
+  materially shortens the live `NodeCanvas::draw()` body even though the file
+  itself is still large.
 
 Write scope:
 - `src/node_stroke_preview.cpp`
@@ -313,7 +320,7 @@ targets look like helpers under one old monolith.
 Status: In Progress
 
 Why now:
-`src/app_layout.cpp` is still a 229-line mixed file that builds menus,
+`src/app_layout.cpp` is still a 125-line mixed file that builds menus,
 attaches callbacks, computes planner inputs, and mutates UI state directly.
 
 Current slice:
@@ -348,6 +355,9 @@ Current slice:
   layout/bootstrap composition.
 - Brush-refresh now also lives in `src/app_layout_brush.cpp`, and
   `src/app_layout.cpp` is down to the remaining layout/bootstrap composition.
+- Layout bootstrap plus reload/load continuation wiring now also lives in
+  `src/app_layout_bootstrap.cpp`, and `src/app_layout.cpp` is down to thin
+  call-through entrypoints plus the remaining local helper pocket.
 
 Write scope:
 - `src/app_layout.cpp`
@@ -505,6 +515,9 @@ Current slice:
   conversion, `UnadjustWindowRectEx`, and GL debug pre/post callbacks now also
   live in `src/platform_windows/windows_bootstrap_helpers.cpp` instead of
   `src/main.cpp`
+- the WMI startup probe now also lives in
+  `src/platform_windows/windows_bootstrap_helpers.cpp` instead of
+  `src/main.cpp`
 - Win32 lifecycle running-state, close/shutdown handling, FPS title update and
   wakeup posting, stylus frame update, window preference save, and VR
   lifecycle wrappers now also live in