fix: session reconnect catch-up, always-on input, frozen session recovery (#524)

- WebSocketContext: emit 'websocket-reconnected' on onopen when it's a reconnect
  (hasConnectedRef tracks first-connect vs. subsequent reconnects).
- useChatRealtimeHandlers: handle 'websocket-reconnected' via onWebSocketReconnect
  callback; added to globalMessageTypes to bypass sessionId mismatch checks.
- ChatInterface: on reconnect, re-fetch JSONL session history so messages missed
  during iOS background are shown immediately. Also resets isLoading and
  canAbortSession so a dead/restarted session no longer freezes the UI forever.
- ChatComposer: remove disabled={isLoading} from textarea — users can always
  type regardless of processing state; submit button still prevents double-send.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

src/contexts/WebSocketContext.tsx

@@ -29,6 +29,7 @@ const buildWebSocketUrl = (token: string | null) => {
 const useWebSocketProviderState = (): WebSocketContextType => {
   const wsRef = useRef<WebSocket | null>(null);
   const unmountedRef = useRef(false); // Track if component is unmounted
+  const hasConnectedRef = useRef(false); // Track if we've ever connected (to detect reconnects)
   const [latestMessage, setLatestMessage] = useState<any>(null);
   const [isConnected, setIsConnected] = useState(false);
   const reconnectTimeoutRef = useRef<NodeJS.Timeout | null>(null);
@@ -61,6 +62,11 @@ const useWebSocketProviderState = (): WebSocketContextType => {
       websocket.onopen = () => {
         setIsConnected(true);
         wsRef.current = websocket;
+        if (hasConnectedRef.current) {
+          // This is a reconnect — signal so components can catch up on missed messages
+          setLatestMessage({ type: 'websocket-reconnected', timestamp: Date.now() });
+        }
+        hasConnectedRef.current = true;
       };
 
       websocket.onmessage = (event) => {