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`.

docs/modernization/tasks.md

@@ -98,6 +98,11 @@ Current slice:
 - `src/platform_windows/windows_runtime_shell.h` is thinner again and now
   imports that binding surface from `windows_runtime_state.h` instead of
   declaring shell-owned bind/release accessors itself.
+- `src/platform_windows/windows_lifecycle_shell.cpp` now formats the FPS title
+  with a stack buffer at the callsite instead of keeping a retained
+  lifecycle-global scratch array.
+- `src/platform_windows/windows_lifecycle_state.*` is now down to the 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.
 - `src/platform_windows/windows_runtime_flow.cpp` is now only a thin handoff

src/platform_windows/windows_lifecycle_shell.cpp

@@ -40,7 +40,7 @@ void update_stylus_frame(float dt)
 
 void update_window_fps(HWND hWnd, const wchar_t* window_title, VrShellState& vr, int frames)
 {
-    auto* title_fps = retained_window_fps_title_buffer();
+    wchar_t title_fps[512]{};
     const int vr_fps = current_vr_fps(vr);
     if (read_vr_session_snapshot(vr).vr_active)
         swprintf_s(title_fps, 512, L"%s - %d fps - %d vr fps", window_title, frames, vr_fps);

src/platform_windows/windows_lifecycle_state.cpp

@@ -7,7 +7,6 @@ namespace {
 
 struct RetainedWindowLifecycleState final {
     std::atomic<int> running{-1};
-    wchar_t title_fps[512]{};
 };
 
 [[nodiscard]] RetainedWindowLifecycleState& retained_window_lifecycle_state() noexcept
@@ -38,9 +37,4 @@ std::atomic<int>& retained_lifecycle_running_state() noexcept
     return retained_window_lifecycle_state().running;
 }
 
-wchar_t* retained_window_fps_title_buffer() noexcept
-{
-    return retained_window_lifecycle_state().title_fps;
-}
-
 }

src/platform_windows/windows_lifecycle_state.h

@@ -10,6 +10,5 @@ void mark_lifecycle_running() noexcept;
 void mark_lifecycle_stopped() noexcept;
 [[nodiscard]] bool lifecycle_is_running() noexcept;
 [[nodiscard]] std::atomic<int>& retained_lifecycle_running_state() noexcept;
-[[nodiscard]] wchar_t* retained_window_fps_title_buffer() noexcept;
 
 }