v8: notifications - browser push notifications and terminal bell/title

Web UI:
- Requests browser notification permission on load
- Shows desktop notification for messages from others when tab unfocused
- Tab title shows unread count: "(3) Chat"
- Resets on focus

Terminal client:
- Bell (\a) on messages from others
- Terminal title updates to show sender and preview
- Title resets when user types

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

chat.py

@@ -25,7 +25,7 @@ import html
 import urllib.parse
 
 PORT = 9999
-VERSION = "7"
+VERSION = "8"
 TUNNEL_TARGET = ("185.208.174.152", 22)
 MAX_FILE_SIZE = 1 * 1024 * 1024       # 1 MB per file
 MAX_TOTAL_STORAGE = 50 * 1024 * 1024  # 50 MB total
@@ -248,9 +248,48 @@ $file.onchange = function() {
   this.value = '';
 };
 
+// Notifications
+let notifEnabled = false;
+if ('Notification' in window) {
+  if (Notification.permission === 'granted') { notifEnabled = true; }
+  else if (Notification.permission !== 'denied') {
+    Notification.requestPermission().then(p => { notifEnabled = (p === 'granted'); });
+  }
+}
+
+let unreadCount = 0;
+const baseTitle = document.title;
+
+function notify(data) {
+  // Only notify when tab is not focused and it's not our own message
+  if (document.hasFocus()) return;
+  if (data.user === $name.value.trim()) return;
+  if (data.user === '***') return;
+
+  unreadCount++;
+  document.title = '(' + unreadCount + ') ' + baseTitle;
+
+  if (notifEnabled) {
+    const body = data.file_id
+      ? data.user + ' shared a file: ' + data.filename
+      : data.user + ': ' + data.text.substring(0, 100);
+    const n = new Notification('Chat', { body: body, tag: 'chat-msg' });
+    setTimeout(() => n.close(), 5000);
+  }
+}
+
+window.addEventListener('focus', function() {
+  unreadCount = 0;
+  document.title = baseTitle;
+});
+
 // SSE
 const es = new EventSource('/chat/events');
-es.onmessage = function(e) { addMsg(JSON.parse(e.data)); };
+es.onmessage = function(e) {
+  const data = JSON.parse(e.data);
+  addMsg(data);
+  notify(data);
+};
 es.onerror = function() { addMsg({ts: Date.now()/1000, user: '***', text: 'Connection lost. Retrying…'}); };
 </script>
 </body>
@@ -667,6 +706,22 @@ class ChatClient:
         self.writer: asyncio.StreamWriter | None = None
         self.running = True
 
+    def notify(self, msg: dict):
+        """Send terminal bell + update title for messages from others."""
+        if msg["user"] == self.name or msg["user"] == "***":
+            return
+        # Terminal bell
+        sys.stdout.write("\a")
+        sys.stdout.flush()
+        # OSC title update (works in most terminals: iTerm2, Terminal.app, etc.)
+        preview = msg["text"][:50] if not msg.get("file_id") else f"shared {msg['filename']}"
+        sys.stdout.write(f"\033]0;[NEW] {msg['user']}: {preview}\007")
+        sys.stdout.flush()
+
+    def reset_title(self):
+        sys.stdout.write(f"\033]0;Chat - {self.name}\007")
+        sys.stdout.flush()
+
     def add_message(self, msg: dict):
         t = time.strftime("%H:%M", time.localtime(msg["ts"]))
         cp = user_color_pair(msg["user"], self.name)
@@ -681,6 +736,7 @@ class ChatClient:
             self.messages.append((f" {t}  {msg['user']}: {lines[0]}", cp))
             for extra in lines[1:]:
                 self.messages.append((f"              {extra}", cp))
+        self.notify(msg)
 
     async def recv_loop(self):
         while self.running:
@@ -768,6 +824,8 @@ class ChatClient:
                 await asyncio.sleep(0.05)
                 continue
 
+            self.reset_title()
+
             if isinstance(ch, str):
                 if ch == "\n":
                     if self.input_buf.strip():