Trim Win32 lifecycle retained state

docs/modernization/roadmap.md

@@ -92,6 +92,11 @@ Latest slice:
   entrypoint header that picks up the retained binding surface from
   `windows_runtime_state.h` instead of declaring a second shell-owned binding
   API.
+- `src/platform_windows/windows_lifecycle_shell.cpp` now formats the FPS title
+  with a stack buffer at the callsite instead of routing through a retained
+  lifecycle-global scratch array.
+- `src/platform_windows/windows_lifecycle_state.*` is down to the retained
+  Win32 running flag only; the redundant global FPS-title buffer is gone.
 - `src/platform_windows/windows_runtime_session.*` now owns the bound-session
   Win32 runtime loop/startup/shutdown body that had still been sitting inside
   `windows_runtime_flow.cpp`.