Narrow Win32 runtime shell surface

docs/modernization/roadmap.md

@@ -75,6 +75,15 @@ Latest slice:
   `windows_runtime_flow.cpp`.
 - `src/platform_windows/windows_runtime_flow.cpp` is now a thinner handoff
   layer over that Windows session helper.
+- `src/platform_windows/windows_runtime_shell.h` no longer exposes the removed
+  runtime-session entrypoint or drags bootstrap/splash declarations through the
+  broader shell header surface.
+- `src/platform_windows/windows_runtime_shell.cpp` now hands runtime execution
+  directly to `run_bound_main_window_runtime(...)` instead of keeping a second
+  wrapper around that seam.
+- `src/main.cpp` now includes `windows_bootstrap_helpers.h` directly for
+  `run_winmain_entry(...)` instead of relying on a transitive declaration
+  through the Windows runtime shell header.
 - `src/platform_windows/windows_runtime_flow.*` now owns the Win32 bound-app
   startup/message-loop/shutdown orchestration that used to live in
   `windows_runtime_shell.cpp`.

docs/modernization/tasks.md

@@ -82,6 +82,14 @@ Current slice:
   Win32 runtime loop/startup/shutdown body.
 - `src/platform_windows/windows_runtime_flow.cpp` is now only a thin handoff
   into that session helper.
+- `src/platform_windows/windows_runtime_shell.h` no longer exposes the removed
+  runtime-session entrypoint or carries bootstrap/splash declarations for it.
+- `src/platform_windows/windows_runtime_shell.cpp` now calls
+  `run_bound_main_window_runtime(...)` directly instead of keeping a second
+  wrapper entrypoint around that seam.
+- `src/main.cpp` now includes `windows_bootstrap_helpers.h` directly for
+  `run_winmain_entry(...)` instead of depending on a transitive declaration
+  through the shell header.
 - `src/platform_windows/windows_runtime_flow.*` now owns the Win32 bound-app
   startup/message-loop/shutdown orchestration.
 - `src/platform_windows/windows_runtime_shell.cpp` now delegates that runtime