feat: Add Meshtastic telemetry display and traceroute visualization

Add full telemetry display in node popups including device metrics
(voltage, channel utilization, air TX) and environment sensors
(temperature, humidity, barometric pressure).

Add traceroute functionality with interactive visualization showing
hop paths and SNR values. Includes API endpoints for sending traceroutes
and retrieving results, plus a modal UI for displaying route information.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

routes/meshtastic.py

@@ -521,3 +521,89 @@ def get_nodes():
         'count': len(nodes_list),
         'with_position_count': sum(1 for n in nodes_list if n.get('has_position'))
     })
+
+
+@meshtastic_bp.route('/traceroute', methods=['POST'])
+def send_traceroute():
+    """
+    Send a traceroute request to a mesh node.
+
+    JSON body:
+        {
+            "destination": "!a1b2c3d4",  // Required: target node ID
+            "hop_limit": 7                // Optional: max hops (1-7, default 7)
+        }
+
+    Returns:
+        JSON with traceroute request status.
+    """
+    if not is_meshtastic_available():
+        return jsonify({
+            'status': 'error',
+            'message': 'Meshtastic SDK not installed'
+        }), 400
+
+    client = get_meshtastic_client()
+
+    if not client or not client.is_running:
+        return jsonify({
+            'status': 'error',
+            'message': 'Not connected to Meshtastic device'
+        }), 400
+
+    data = request.get_json(silent=True) or {}
+    destination = data.get('destination')
+
+    if not destination:
+        return jsonify({
+            'status': 'error',
+            'message': 'Destination node ID is required'
+        }), 400
+
+    hop_limit = data.get('hop_limit', 7)
+    if not isinstance(hop_limit, int) or not 1 <= hop_limit <= 7:
+        hop_limit = 7
+
+    success, error = client.send_traceroute(destination, hop_limit=hop_limit)
+
+    if success:
+        return jsonify({
+            'status': 'sent',
+            'destination': destination,
+            'hop_limit': hop_limit
+        })
+    else:
+        return jsonify({
+            'status': 'error',
+            'message': error or 'Failed to send traceroute'
+        }), 500
+
+
+@meshtastic_bp.route('/traceroute/results')
+def get_traceroute_results():
+    """
+    Get recent traceroute results.
+
+    Query parameters:
+        limit: Maximum number of results to return (default: 10)
+
+    Returns:
+        JSON with list of traceroute results.
+    """
+    client = get_meshtastic_client()
+
+    if not client or not client.is_running:
+        return jsonify({
+            'status': 'error',
+            'message': 'Not connected to Meshtastic device',
+            'results': []
+        }), 400
+
+    limit = request.args.get('limit', 10, type=int)
+    results = client.get_traceroute_results(limit=limit)
+
+    return jsonify({
+        'status': 'ok',
+        'results': [r.to_dict() for r in results],
+        'count': len(results)
+    })