Function fire_break 

pub fn fire_break<R: Runtime>(
    app: &AppHandle<R>,
    current_break: &Arc<Mutex<Option<BreakEvent>>>,
    event: BreakEvent,
    placement: MonitorPlacement,
    windowed: bool,
    windowed_fraction: f64,
)

Stash the break event in current_break, position an overlay window on each selected monitor, and emit break:start to the renderer. Used directly for sleep/resume-last paths; normal scheduled breaks go through deliver_break instead.

postpone_available is forced off for enforceable breaks here, so callers can pass the user’s raw intent without re-deriving it.