feat: filter scanner Bluetooth devices from display

- Add bt_mac field to scanner config for identifying scanner BT adapters
- Store bt_mac in peers table for peer scanners
- Filter out devices matching scanner BT MACs from all views
- Prevents scanners from appearing as devices in device lists/maps

Config: scanner.bt_mac = "XX:XX:XX:XX:XX:XX"
API: /api/peers/register accepts bt_mac field

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

config.yaml

@@ -6,12 +6,13 @@ web:
   port: 5000
   debug: false
 scanner:
-  id: ''
-  name: ''
+  id: rpios
+  name: rpios
   latitude: null
   longitude: null
   floor: null
   is_master: true
+  bt_mac: '2C:CF:67:6F:66:AC'
   wifi_interface: wlan0
   bt_scan_timeout: 10
   path_loss_exponent: 2.5