Function record_intentional_focus 

pub unsafe fn record_intentional_focus(child: *mut c_void)

Single write helper called from both intentional-focus sites (the pane subclass in this module and MainFocusReclaimTask in ui_tasks.rs). Resolves child’s top-level ancestor via GetAncestor(GA_ROOT) and stores the pair into LAST_FOCUSED_BY_ROOT.

Safety: child must be a live HWND that the caller intentionally just focused (so the recorded value is meaningful). Caller must also be on the Win32 UI thread, since GetAncestor and the static LazyLock aren’t sensitive to thread but Win32 idiom is to keep HWND traffic on the message-pump thread.