fix(emcn/toast): reset expanded when the stack empties

The hover wrapper unmounts without firing mouse-leave when the last toast goes
(dismiss / clear-all / navigation), so expanded could stay true and stop the
next toasts from auto-dismissing. Force expanded false whenever the stack is
empty.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: waleedlatif1

apps/sim/components/emcn/components/toast/toast.tsx

@@ -522,6 +522,16 @@ export function ToastProvider({ children }: { children?: ReactNode }) {
     setMounted(true)
   }, [])
 
+  /**
+   * Reset the hover-expanded flag whenever the stack empties. The hover wrapper
+   * unmounts without firing mouse-leave when the last toast goes (dismiss / clear
+   * / navigation), so without this `expanded` could stay `true` and stop the next
+   * toasts from auto-dismissing.
+   */
+  useEffect(() => {
+    if (toasts.length === 0) setExpanded(false)
+  }, [toasts.length])
+
   /**
    * Adds a toast. Actionable toasts persist (`duration: 0`) unless an explicit
    * `duration` is given. When the stack exceeds `STACK_LIMIT` the oldest