pub fn register_pool_window(state: &Arc<AppState>, label: &str)Expand description
Called from on_after_created when a pool window’s browser is
registered. Logs + applies WS_EX_TOOLWINDOW so the off-screen
pool window doesn’t show up in the taskbar / Alt+Tab. The
promote path (promote_pool_window) clears it again so the
torn-off window IS taskbar-visible.
Queue insertion still waits for mark_pool_window_renderer_ready
(frontend-side handshake) — without that gate emit_event_to_window
could race the renderer’s listener install and drop the promote
signal.