fix: reset i-MID status on exit and harden system service calls to pr…

[rsilveira]

Hi! This follow-up PR addresses the critical issues reported in #45 and adds stability hardening:

1. i-MID Fix: Explicitly reset i-MID status to 0 on exit.
2. Stability: Added robust error handling for Fujitsu services.
3. Steering: Confirmed index 260 works for HRV/Civic units.

[rsilveira]

I've just pushed a few critical updates to this PR based on real-world testing on a Honda HR-V 2016 unit where the app was previously failing.

Summary of new changes:

1. Guaranteed Audio Release: Removed strict PREINSTALL authorization checks during the exit sequence. This ensures that even when the app is identified as a 'Third Party' (Auth 1), it explicitly notifies the Fujitsu ModeMgr to release audio control. This fixes the 'Fujitsu error' and ensures the native FM Radio/Bluetooth resumes immediately after exiting ODA.
2. Steering Wheel Index: Re-confirmed and set the default steeringWheelIdx to 260. Testing showed this index is consistent for 2016 HRV/Civic units for track/seek controls.
3. i-MID Sync: Added notifyModeMgrStatus(idx, 0) during shutdown. This was the missing link that was causing the head unit to stay in an inconsistent state, leading to crashes in native services like tunerapp.
4. Improved Registration: Unified the steering wheel callback registration to happen as soon as the service connects, regardless of the app's internal authorization state.

These changes significantly harden the app's stability on legacy Fujitsu-Ten units.