fix(lazy-connect): harden connection lifecycle against race conditions and edge cases

- Prevent concurrent connect() by removing isConnecting reset from
  forceDisconnect(); the guard in connect() now reliably blocks
  re-entry since no external caller can defeat it.
- Reset isConnecting at end of connect() so subsequent calls can
  proceed without waiting for the async '40' handler.
- Clear connectIntent and cancel reconnect timer on server ERROR
  when no currentRoom exists, preventing infinite reconnect loops
  after failed join attempts (e.g. wrong password via invite link).
- Move connectIntent assignment after !roomId guard in
  WEB_JOIN_REQUEST to avoid clobbering existing intent on invalid
  input.
- Broadcast JOIN_STATUS failure to popup and bridge tabs when
  WEB_JOIN_REQUEST receives an invalid room ID, so the website
  join page receives feedback instead of hanging forever.
- Clear joinBtnTimeout on CONNECTION_STATUS connected/disconnected
  to avoid stale timeout error messages in the popup.

extension/background.js

@@ -343,7 +343,6 @@ function forceDisconnect() {
         socket = null;
     }
     currentServerUrl = null;
-    isConnecting = false;
     isNamespaceJoined = false;
     isForceSyncInitiator = false;
     expectedAcksCount = 0;
@@ -606,6 +605,8 @@ async function connect() {
             addLog('WebSocket Error: Connection failed', logType);
         };
 
+        isConnecting = false;
+
     } catch (e) {
         isConnecting = false;
         const logType = reconnectAttempts > 1 ? 'error' : 'warn';
@@ -856,6 +857,14 @@ function handleServerEvent(event, data) {
             break;
         case EVENTS.ERROR:
             isConnecting = false;
+            // If we get a server error before successfully joining a room,
+            // clear connectIntent to prevent an infinite reconnect loop.
+            if (!currentRoom) {
+                connectIntent = false;
+                if (reconnectTimer) { clearTimeout(reconnectTimer); reconnectTimer = null; }
+                reconnectAttempts = 0;
+                reconnectFailed = false;
+            }
             broadcastConnectionStatus('disconnected');
             addLog(`Server Error: ${data.message}`, 'error');
             chrome.storage.local.get(['browserNotifications', 'locale'], async (settings) => {
@@ -1554,8 +1563,16 @@ async function handleAsyncMessage(message, sender, sendResponse) {
     } else if (message.type === 'WEB_JOIN_REQUEST') {
         const { roomId: rawRoomId, password, useCustomServer, serverUrl } = message;
         const roomId = typeof rawRoomId === 'string' ? rawRoomId.replace(/[^a-zA-Z0-9\-]/g, '') : '';
-        connectIntent = !!roomId;
-        if (!roomId) { sendResponse({ error: 'invalid_room_id' }); return; }
+        if (!roomId) {
+            const errMsg = { type: 'JOIN_STATUS', success: false, message: 'Invalid room ID' };
+            chrome.runtime.sendMessage(errMsg).catch(() => {});
+            chrome.tabs.query({}, (tabs) => {
+                tabs.forEach(tab => chrome.tabs.sendMessage(tab.id, errMsg).catch(() => {}));
+            });
+            sendResponse({ status: 'invalid_room_id' });
+            return;
+        }
+        connectIntent = true;
         chrome.storage.local.set({ 
             roomId, 
             password,

extension/popup.js

@@ -1623,6 +1623,9 @@ chrome.runtime.onMessage.addListener((msg) => {
         updatePeerList(msg.peers);
         if (msg.peers) detectPeerChanges(msg.peers);
     } else if (msg.type === 'CONNECTION_STATUS') {
+        if (msg.status === 'connected' || msg.status === 'disconnected') {
+            if (joinBtnTimeout) { clearTimeout(joinBtnTimeout); joinBtnTimeout = null; }
+        }
         if (msg.status === 'connected') {
             clearConnectionErrorTimer();
         }