Bug Report: GPS Signal Loss and Incorrect Recalibration in Tunnel

Title: GPS Signal Loss in Tunnel Causes Route to Jump to Incorrect Location (France)

Description:
While navigating a route from Klagenfurt to Graz Airport (GRZ) on 13-09-2026, the app lost GPS signal in a tunnel. After exiting the tunnel, the route incorrectly recalibrated our position to France (as seen in the screenshot), despite the last known location being in Austria. This resulted in:

• A 2,256 km detour (2 trips, 2 Std. 52 Min. total).

• Speed and energy consumption data were also affected (e.g., 786 km/h average speed, 0.0 kWh energy used).

Steps to Reproduce:

1. Start a route from Klagenfurt to Graz Airport (GRZ).

2. Enter a tunnel (e.g., likely the Plabutschtunnel or similar on the A2 Autobahn).

3. Observe GPS signal loss and subsequent recalibration to an incorrect location (France in this case).

Expected Behavior:

• The app should retain the last known GPS location and resume tracking accurately after signal recovery.

• If signal loss is prolonged, offline-tiled maps or dead reckoning (using speed/accelerometer data) should prevent jumps to out-of-bounds locations.

• No recalibration to a location outside the route’s geographical bounds (e.g., France for a route entirely within Austria).

Suggested Fixes:

1. Offline-Tiled Maps: Implement offline map tiles to maintain positional accuracy during GPS blackouts.

2. Geofenced Recalibration: Limit GPS recalibration to a reasonable radius (e.g., 50 km) from the last known location to avoid absurd jumps.

3. Dead Reckoning: Use vehicle speed/accelerometer data to estimate position when GPS is lost.

4. User Alerts: Notify users when GPS signal is lost/recovered and show a warning if the recalibrated position is unrealistic.