BLE scanner filtering for TAP devices

Before this change, MapXr's Bluetooth scanner would surface every BLE device in range: phones, headphones, fitness trackers, smart lightbulbs, all of it. Useful for debugging, but not something you want to ship to users.

How TAP Strap devices advertise

TAP Strap devices include a known service UUID in their BLE advertisement packets. By filtering scan results to only those that include this UUID, we can limit the device list to genuine TAP Straps without requiring any connection attempt first.

The filter is applied in the btleplug scan filter configuration, so unrelated devices never even reach MapXr's application layer. The OS-level BLE stack discards them before they're passed up.

Why this matters

Beyond the obvious UX improvement, filtering also reduces the churn of advertisement events that the application needs to process. In a busy BLE environment (an office, a coffee shop) an unfiltered scan can receive dozens of advertisement packets per second. Filtering to TAP devices only reduces that to essentially zero noise between actual device events.