Thin Windows entry, preview shell, and platform legacy state

docs/modernization/roadmap.md

@@ -1,7 +1,7 @@
 # PanoPainter Modernization Roadmap
 
 Status: live
-Last updated: 2026-06-16
+Last updated: 2026-06-17
 
 This roadmap is now architecture-first.
 The active execution queue lives in `docs/modernization/tasks.md`.
@@ -80,18 +80,34 @@ What is still carrying too much live ownership:
 Current hotspot files:
 
 - `src/canvas.cpp`: 17 lines
-- `src/app_layout.cpp`: 125 lines
+- `src/app_layout.cpp`: 109 lines
 - `src/canvas_modes.cpp`: 1 line
 - `src/node.cpp`: 12 lines
-- `src/main.cpp`: 87 lines
+- `src/main.cpp`: 10 lines
 - `src/node_panel_brush.cpp`: 2 lines
-- `src/node_stroke_preview.cpp`: 160 lines
-- `src/node_canvas.cpp`: 85 lines
+- `src/node_stroke_preview.cpp`: 76 lines
+- `src/node_canvas.cpp`: 69 lines
 - `src/app.cpp`: 94 lines
 - `src/app_dialogs.cpp`: 95 lines
 
 Latest slice:
 
+- The live Windows entry shell now routes through
+  `run_main_application(...)` in
+  `src/platform_windows/windows_runtime_shell.*`, leaving `src/main.cpp` as a
+  minimal entry wrapper around `main(...)` and `WinMain(...)`.
+- Retained legacy storage-path state now lives in
+  `src/platform_legacy/legacy_platform_state.*` instead of staying inline in
+  `src/platform_legacy/legacy_platform_services.cpp`, which trims another
+  process-global platform-state pocket out of the legacy platform shell.
+- The remaining `NodeStrokePreview` clone-init, stroke-frame planning,
+  mix-pass adapter wiring, sample-pass adapter wiring, and immediate-draw
+  request construction now route through
+  `src/legacy_node_stroke_preview_runtime_services.*`,
+  `src/legacy_node_stroke_preview_draw_services.*`, and
+  `src/legacy_node_stroke_preview_sample_services.*`, leaving
+  `src/node_stroke_preview.cpp` as a thinner live adapter.
+
 - `NodeCanvas::handle_event()` now routes through
   `handle_legacy_node_canvas_event(...)` in
   `src/legacy_canvas_tool_services.*`, leaving `src/node_canvas.cpp` as a much