chore: Bump version to v2.18.0

Bluetooth enhancements (service data inspector, appearance codes, MAC
cluster tracking, behavioral flags, IRK badges, distance estimation),
ACARS SoapySDR multi-backend support, dump1090 stale process cleanup,
GPS error state, and proximity radar/signal card UI improvements.

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

utils/bluetooth/aggregator.py

@@ -606,6 +606,12 @@ class DeviceAggregator:
 
         return result
 
+    def get_fingerprint_mac_count(self, fingerprint_id: str) -> int:
+        """Return how many distinct device_ids share a fingerprint."""
+        with self._lock:
+            device_ids = self._fingerprint_to_devices.get(fingerprint_id)
+            return len(device_ids) if device_ids else 0
+
     def prune_ring_buffer(self) -> int:
         """Prune old observations from ring buffer."""
         return self._ring_buffer.prune_old()