Thin canvas state, tools menu, and node canvas draw

docs/modernization/tasks.md

@@ -87,11 +87,18 @@ looks like a wrapper around the old renderer shell.
 
 #### ARC-RND-001 - Split `canvas.cpp` Into Document State And Render Execution Shells
 
-Status: Ready
+Status: In Progress
 
 Why now:
 `src/canvas.cpp` is still the biggest single architectural blocker at about
-4128 lines.
+3622 lines.
+
+Current slice:
+- Canvas state-management helpers for picking, clear/clear-all, layer
+  add/remove/order/lookups, animation frame control, resize, and snapshot
+  save/restore now live in `src/legacy_canvas_state_services.cpp` instead of
+  staying inline in `src/canvas.cpp`, but the file still owns the larger
+  document-plus-render shell.
 
 Write scope:
 - `src/canvas.cpp`
@@ -171,6 +178,11 @@ Current slice:
   now also routes through `execute_legacy_canvas_draw_merge_layer_plane(...)`,
   but the node still owns substantial live layer traversal and renderer state
   orchestration.
+- `NodeCanvas` post-draw callback assembly now also routes through
+  `execute_legacy_canvas_draw_merge_post_draw_callbacks(...)`, and the
+  remaining per-layer render-path orchestration now also routes through
+  `execute_legacy_canvas_draw_merge_layer_path(...)`, but the node still owns
+  broader draw-loop and renderer-state shell sequencing.
 
 Write scope:
 - `src/node_stroke_preview.cpp`
@@ -246,12 +258,18 @@ targets look like helpers under one old monolith.
 
 #### ARC-APP-001 - Split `app_layout.cpp` Into UI Binding Modules
 
-Status: Ready
+Status: In Progress
 
 Why now:
-`src/app_layout.cpp` is still a 2026-line mixed file that builds menus,
+`src/app_layout.cpp` is still a 1498-line mixed file that builds menus,
 attaches callbacks, computes planner inputs, and mutates UI state directly.
 
+Current slice:
+- Tools-menu UI binding, including the nested panels/options submenu wiring,
+  now lives in `src/app_layout_tools_menu.cpp`, and `App::init_menu_tools()`
+  is now a thin call-through, but file/about/layer/sidebar and broader layout
+  composition are still inline in `src/app_layout.cpp`.
+
 Write scope:
 - `src/app_layout.cpp`
 - `src/legacy_app_shell_services.*`