fix(chat): prevent poll-triggered reload after send by using server timestamp

The 60s checkForUpdates poll was detecting has_updates due to clock skew
between client and server timestamps. Now the send API returns the server
timestamp, and the frontend uses it for markChannelAsRead — ensuring the
poll sees no updates for own sent messages.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/device_manager.py

@@ -1252,7 +1252,7 @@ class DeviceManager:
                     'id': msg_id,
                 }, namespace='/chat')
 
-            return {'success': True, 'message': 'Message sent', 'id': msg_id}
+            return {'success': True, 'message': 'Message sent', 'id': msg_id, 'timestamp': ts}
 
         except Exception as e:
             logger.error(f"Failed to send channel message: {e}")

app/meshcore/cli.py

@@ -60,20 +60,17 @@ def recv_messages() -> Tuple[bool, str]:
     return True, "Messages are received automatically via events"
 
 
-def send_message(text: str, reply_to: Optional[str] = None, channel_index: int = 0) -> Tuple[bool, str, Optional[int]]:
-    """Send a message to a channel. Returns (success, message, msg_id)."""
+def send_message(text: str, reply_to: Optional[str] = None, channel_index: int = 0) -> Dict:
+    """Send a message to a channel. Returns result dict with id and timestamp."""
     if reply_to:
         text = f"@[{reply_to}] {text}"
 
     try:
         dm = _get_dm()
-        result = dm.send_channel_message(channel_index, text)
-        if result['success']:
-            return True, result.get('message', 'Message sent'), result.get('id')
-        return False, result.get('error', 'Failed to send message'), None
+        return dm.send_channel_message(channel_index, text)
     except Exception as e:
         logger.error(f"send_message error: {e}")
-        return False, str(e), None
+        return {'success': False, 'error': str(e)}
 
 
 # =============================================================================

app/routes/api.py

@@ -601,21 +601,22 @@ def send_message():
         channel_idx = data.get('channel_idx', 0)
 
         # Send message via meshcli
-        success, message, msg_id = cli.send_message(text, reply_to=reply_to, channel_index=channel_idx)
+        result = cli.send_message(text, reply_to=reply_to, channel_index=channel_idx)
 
-        if success:
+        if result['success']:
             # v2: Echo tracking is handled automatically by DeviceManager events
 
             return jsonify({
                 'success': True,
                 'message': 'Message sent successfully',
                 'channel_idx': channel_idx,
-                'id': msg_id,
+                'id': result.get('id'),
+                'timestamp': result.get('timestamp'),
             }), 200
         else:
             return jsonify({
                 'success': False,
-                'error': message
+                'error': result.get('error', 'Failed to send message')
             }), 500
 
     except Exception as e:

app/static/js/app.js

@@ -1325,6 +1325,10 @@ async function sendMessage() {
                 const wrapper = document.querySelector(`.message-wrapper[data-msg-id="${optimisticId}"]`);
                 if (wrapper) wrapper.dataset.msgId = data.id;
             }
+            // Use server timestamp to prevent poll-triggered reload due to clock skew
+            if (data.timestamp) {
+                markChannelAsRead(currentChannelIdx, data.timestamp);
+            }
         } else {
             showNotification('Failed to send: ' + data.error, 'danger');
         }