Indoor Positioning System Enhancement

I’ve built a prototype Indoor Positioning System using BLE beacons and a Raspberry Pi that:

- Scans for beacon RSSI values (Python script on Pi)
- Sends RSSI data to a .NET 8 backend (ASP.NET Core Web API)
- Calculates user location using trilateration (Kalman filter included)
- Displays user position and orientation on a Leaflet map
- Has a custom floorplan image that should overlay correctly on Building 50

Your tasks:
- Connect via Tailscale VPN and SSH into the Pi (access will be provided)
- Ensure BLE scanning script runs at boot and sends values correctly
- Verify backend endpoint /api/position/user-location responds with accurate coordinates
- Fix the image overlay alignment (should display directly over building 50)
- Make sure that the arrow (user's pointer on the map) moves on the map
- Ensure the arrow (user's pointer on the map) marker moves in real time and rotates with phone orientation
- cooperate with me to solve the problem


Tech stack:
- Python 3 on Raspberry Pi for BLE scanning
- .NET 8 Web API backend (with EF Core + Swagger)
- SQL Server for storage
- Leaflet + vanilla JS frontend
- Kalman filter and trilateration are already implemented