fix email store lazy load

app/(main)/[locale]/page.tsx

@@ -110,6 +110,7 @@ export default function Home() {
   const [isProtocolAccountSwitching, setIsProtocolAccountSwitching] = useState(false);
   const markAsReadTimeoutRef = useRef<NodeJS.Timeout | null>(null);
   const lastUndoToastSubmissionRef = useRef<string | null>(null);
+  const initialMailLoadClientRef = useRef<object | null>(null);
   const { isAuthenticated, client, logout, checkAuth, switchAccount, activeAccountId, isLoading: authLoading, connectionLost, isRateLimited, rateLimitUntil } = useAuthStore();
   const { identities } = useIdentityStore();
   useIdentitySync();
@@ -914,18 +915,26 @@ export default function Home() {
   }, [isAuthenticated, client, handleMailtoProtocolRequest]);
 
   // Fallback fetch for paths that didn't go through login()'s prefetch
-  // (notably checkAuth on page refresh). The prefetch in auth-store/login()
-  // populates mailboxes before this effect first runs, so on the post-login
-  // path this block is a no-op.
+  // (notably checkAuth on page refresh). Settings pages can also prefill
+  // mailboxes without emails, so bootstrap emails once per client when the
+  // mail route mounts even if mailbox data is already present.
   useEffect(() => {
-    if (isAuthenticated && client && mailboxes.length === 0) {
+    if (!isAuthenticated || !client) {
+      initialMailLoadClientRef.current = null;
+      return;
+    }
+
+    if (initialMailLoadClientRef.current === client) return;
+    initialMailLoadClientRef.current = client;
+
     let retryTimer: ReturnType<typeof setTimeout> | null = null;
     let cancelled = false;
 
     const loadData = async (attempt = 1) => {
       try {
+        const needsMailboxes = useEmailStore.getState().mailboxes.length === 0;
         await Promise.all([
-            fetchMailboxes(client),
+          needsMailboxes ? fetchMailboxes(client) : Promise.resolve(),
           fetchQuota(client)
         ]);
 
@@ -951,6 +960,7 @@ export default function Home() {
         fetchTagCounts(client);
       } catch (error) {
         console.error('Error loading email data:', error);
+        initialMailLoadClientRef.current = null;
       }
     };
     loadData();
@@ -959,8 +969,7 @@ export default function Home() {
       cancelled = true;
       if (retryTimer) clearTimeout(retryTimer);
     };
-    }
-  }, [isAuthenticated, client, mailboxes.length, fetchMailboxes, fetchEmails, fetchQuota, fetchTagCounts, refreshScheduledMetadata]);
+  }, [isAuthenticated, client, fetchMailboxes, fetchEmails, fetchQuota, fetchTagCounts, refreshScheduledMetadata]);
 
   // Push notifications: set up once per client and tear down when the client
   // goes away (logout or account switch). Kept separate from the fetch effect