feat: add terminal broadcast, context menu, and shell close

Complete multi-pane broadcast, standard terminal right-click actions, batch host selection with progress, and native ssh_close_shell so closing a pane tears down the remote shell.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/components/sessions/QuickConnectDialog.tsx

@@ -69,10 +69,11 @@ export default function QuickConnectDialog({ isOpen, onClose, initialTarget = ''
   const [error, setError] = useState<string | null>(null)
 
   useEffect(() => {
-    if (isOpen && initialTarget) {
-      setTarget(initialTarget)
-      setError(null)
-    }
+    if (!isOpen) return
+    setTarget(initialTarget)
+    setPassword('')
+    setError(null)
+    setIsConnecting(false)
   }, [initialTarget, isOpen])
 
   const handleSubmit = async () => {