Extract main toolbar and thin startup/node helpers

docs/modernization/roadmap.md

@@ -80,10 +80,10 @@ What is still carrying too much live ownership:
 Current hotspot files:
 
 - `src/canvas.cpp`: 2645 lines
-- `src/app_layout.cpp`: 785 lines
+- `src/app_layout.cpp`: 743 lines
 - `src/canvas_modes.cpp`: 1798 lines
-- `src/node.cpp`: 1551 lines
-- `src/main.cpp`: 882 lines
+- `src/node.cpp`: 1594 lines
+- `src/main.cpp`: 1098 lines
 - `src/node_panel_brush.cpp`: 1197 lines
 - `src/node_stroke_preview.cpp`: 933 lines
 - `src/node_canvas.cpp`: 910 lines
@@ -140,10 +140,13 @@ Current architecture mismatches that must be treated as real blockers:
   `src/app_layout_about_layer_menu.cpp` and `App::init_menu_about()` plus
   `App::init_menu_layer()` are now thin call-throughs, while sidebar panel
   binding and popup wiring now also live in `src/app_layout_sidebar.cpp` and
-  `App::init_sidebar()` is now a thin call-through, while the informational
-  overlay opener family now also lives in `src/app_dialogs_info_openers.cpp`
-  and the corresponding `App::dialog_*` entrypoints are thinner, while the
-  export/video/PPBR dialog family now also lives in
+  `App::init_sidebar()` is now a thin call-through, while main-toolbar binding
+  now also lives in `src/app_layout_main_toolbar.cpp` and
+  `App::init_toolbar_main()` is now a thin call-through, while the
+  informational overlay opener family now also lives in
+  `src/app_dialogs_info_openers.cpp` and the corresponding `App::dialog_*`
+  entrypoints are thinner, while the export/video/PPBR dialog family now also
+  lives in
   `src/app_dialogs_export.cpp` and those `App::dialog_*` entrypoints are
   thinner too, while new/open/save/browse/resize workflow entrypoints now also
   live in `src/app_dialogs_workflow.cpp` and `src/app_dialogs.cpp` is now
@@ -183,6 +186,12 @@ Current architecture mismatches that must be treated as real blockers:
   sequencing, FPS title update/wakeup posting, stylus frame update, window
   preference save, and VR lifecycle wrappers now also live in
   `src/platform_windows/windows_lifecycle_shell.cpp` instead of `src/main.cpp`,
+  while the Win32 startup/window/bootstrap path in `src/main.cpp` now also
+  routes through named local helper functions for runtime-data discovery,
+  startup-state initialization, window creation, pixel-format setup, GL loader
+  init, runtime-info logging, and core-context upgrade sequencing even though
+  that state still needs to move into platform-owned modules for the file to
+  shrink materially,
   while `App::rec_loop()` now delegates worker-iteration orchestration into
   the retained recording bridge, `App::update_rec_frames()` now delegates
   recording label refresh through that same retained recording path, and the
@@ -198,7 +207,11 @@ Current architecture mismatches that must be treated as real blockers:
   document-IO cluster now lives in `src/legacy_canvas_document_io_services.cpp`
   and `NodeStrokePreview` render-target setup plus immediate-pass sequencing
   now route through retained preview execution helpers, even though the bridge
-  still owns worker-side readback flow and encoder-state label reads.
+  still owns worker-side readback flow and encoder-state label reads, while
+  `Node` child attach/detach/reorder operations now route through named local
+  helpers in `src/node.cpp`, which makes the scene-graph mutation paths easier
+  to reason about without yet reducing the file or moving ownership into
+  `pp_ui_core`.
 - Modern C++23 usage exists in extracted components, especially `std::span`,
   explicit result/status objects, and a few concepts, but the live app still
   does not consistently express ownership, thread affinity, or renderer