Gmail label sync + no-dup backfill, live label/UI updates, account-delete cleanup, Sync-SPAM toggle, sidebar logo

Gmail sync (SPEC: Gmail sync):
- Provider fetches X-GM-LABELS when X-GM-EXT-1 is advertised; parses custom labels
  (system labels dropped, mUTF-7 decoded) onto RemoteMessage.
- Engine syncs only system folders + All Mail for Gmail, skips every label folder,
  and dedupes the All Mail pass by Message-ID — kills the INBOX/All-Mail duplication.
- Custom labels ride the message.new event; the labels plugin subscribes and maps
  them to chips as "<name> [Gmail]" (per-message + thread aggregate + known set),
  so labels fill in gradually with the sync window. Non-ASCII labels decode right.

Labels self-healing (message-driven reconcile):
- Per-message keys are the source of truth; t: aggregates and _labels are derived.
  Reconcile drops labels of deleted messages, regroups survivors by their current
  thread (fixing JWZ thread merges), rewrites changed t: keys, and rebuilds _labels
  from live messages — keeping user labels, dropping orphaned Gmail ones.
- New SDK reads: sdk.threads.existing / sdk.messages.threads_of. Sidebar refreshes
  live via a plugin.labels.changed WS event on new labels.

Account deletion: prune threads left empty after the cascade (they were user-scoped,
so only messages cascaded) + de-list the account from surviving cross-account threads.

Sync SPAM: opt-in per-account sync_spam (migration 0015, default off) — the engine
skips the Junk folder in backfill and poll unless enabled; wizard checkbox added.

Robustness / UX:
- WebSocket auto-reconnects with backoff and resyncs on (re)connect, and account
  add/delete invalidates threads/labels — no more hard refresh for live updates.
- Backfill banner + sidebar ring also require done < total, so a completed account
  can't leave a stuck "X of X".
- Scrub lone UTF-16 surrogates from parsed headers/bodies so bad messages no longer
  crash the backfill on Postgres text/JSONB.
- Ultimo signet logo in the Mail/Calendar/Contacts sidebar header (and at the top of
  the collapsed rail), via the shared plugin-ui.css + MailLayout.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01U72FZiF1W1pb8XxyWBTREA

frontend/src/lib/ws.ts

@@ -37,15 +37,29 @@ export function subscribeWs(listener: WsListener): () => void {
 
 export function connectWs(queryClient: QueryClient): () => void {
   const proto = window.location.protocol === "https:" ? "wss" : "ws";
-  const socket = new WebSocket(`${proto}://${window.location.host}/api/ws`);
+  const url = `${proto}://${window.location.host}/api/ws`;
 
-  const ping = window.setInterval(() => {
-    if (socket.readyState === WebSocket.OPEN) {
-      socket.send(JSON.stringify({ type: "ping" }));
+  let socket: WebSocket | null = null;
+  let ping: number | undefined;
+  let reconnectTimer: number | undefined;
+  let attempts = 0;
+  let stopped = false;
+
+  // Refetch the live-updated lists — used on every (re)connect so a dropped socket
+  // (server restart, sleep, network blip) self-heals and catches up on missed events.
+  const resync = () => {
+    for (const key of [
+      ["threads"],
+      ["accounts"],
+      ["folder-counts"],
+      ["quota"],
+      ["drafts-remote"],
+    ]) {
+      queryClient.invalidateQueries({ queryKey: key });
     }
-  }, 30000);
+  };
 
-  socket.onmessage = (event) => {
+  const handleMessage = (event: MessageEvent) => {
     let parsed: unknown;
     try {
       parsed = JSON.parse(event.data);
@@ -87,7 +101,15 @@ export function connectWs(queryClient: QueryClient): () => void {
       queryClient.invalidateQueries({ queryKey: ["folder-counts"] });
     }
     if (name === "account.state_changed") {
+      // Adding/deleting an account changes threads and (Gmail) labels wholesale —
+      // refetch the list, chips, and sidebar so nothing stale lingers.
       queryClient.invalidateQueries({ queryKey: ["accounts"] });
+      queryClient.invalidateQueries({ queryKey: ["threads"] });
+      queryClient.invalidateQueries({ queryKey: ["thread-labels"] });
+      queryClient.invalidateQueries({ queryKey: ["message-labels"] });
+      queryClient.invalidateQueries({ queryKey: ["labels-all"] });
+      queryClient.invalidateQueries({ queryKey: ["folder-counts"] });
+      window.dispatchEvent(new Event("webmail:labels-changed"));
     }
     if (name === "message.sent") {
       // The sent message's draft is deleted server-side; refresh the Drafts list.
@@ -96,8 +118,35 @@ export function connectWs(queryClient: QueryClient): () => void {
     }
   };
 
+  const connect = () => {
+    socket = new WebSocket(url);
+    socket.onopen = () => {
+      attempts = 0;
+      ping = window.setInterval(() => {
+        if (socket?.readyState === WebSocket.OPEN) {
+          socket.send(JSON.stringify({ type: "ping" }));
+        }
+      }, 30000);
+      resync(); // catch up on anything published while we were disconnected
+    };
+    socket.onmessage = handleMessage;
+    socket.onclose = () => {
+      if (ping !== undefined) window.clearInterval(ping);
+      if (stopped) return;
+      // Exponential backoff, capped at 30s, so a downed server is retried politely.
+      const delay = Math.min(30000, 1000 * 2 ** attempts);
+      attempts += 1;
+      reconnectTimer = window.setTimeout(connect, delay);
+    };
+    socket.onerror = () => socket?.close(); // route errors through onclose -> reconnect
+  };
+
+  connect();
+
   return () => {
-    window.clearInterval(ping);
-    socket.close();
+    stopped = true;
+    if (ping !== undefined) window.clearInterval(ping);
+    if (reconnectTimer !== undefined) window.clearTimeout(reconnectTimer);
+    socket?.close();
   };
 }