feat: Add cross-mode analytics dashboard with geofencing, correlations, and data export

Adds a unified analytics mode under the Security nav group that aggregates
data across all signal modes. Includes emergency squawk alerting (7700/7600/7500),
vertical rate anomaly detection, ACARS/VDL2-to-ADS-B flight correlation,
geofence zones with enter/exit detection for aircraft/vessels/APRS stations,
temporal pattern detection, RSSI history tracking, Meshtastic topology mapping,
and JSON/CSV data export.

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

routes/meshtastic.py

@@ -1051,3 +1051,19 @@ def request_store_forward():
             'status': 'error',
             'message': error or 'Failed to request S&F history'
         }), 500
+
+
+@meshtastic_bp.route('/topology')
+def mesh_topology():
+    """Return mesh network topology graph."""
+    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'}), 400
+
+    return jsonify({
+        'status': 'success',
+        'topology': client.get_topology(),
+    })