[iOS] After upgrading to 10.x, Live Activity no longer shows remaining time

[umbertogrimaldi]

Which API doesn't behave as documented, and how does it misbehave?
On iOS, after upgrading just_audio to 10.x, the system Live Activity / Now Playing no longer shows playback progress or remaining time.
Specifically, the elapsed time and duration that previously appeared on the lock screen scrub bar are not shown anymore. This looks like the iOS Now Playing info (elapsed time / duration) is no longer being updated from AudioPlayer (e.g., duration, position), so the scrub bar and remaining seconds are missing.

Minimal reproduction project
The example (play any track with a known duration and lock the screen).

To Reproduce (i.e. user steps, not code)
Steps to reproduce the behavior:

1. Upgrade to just_audio 10.x.
2. Start playback of any file with a finite duration.
3. Lock the device and view the iOS Live Activity / lock-screen player.
4. Observe that the scrub bar shows no progress and no remaining time in seconds.

Error messages

Expected behavior
The iOS Live Activity / lock-screen player should display the scrub bar progress and remaining time (as it did on previous just_audio versions).

Screenshots

Desktop (please complete the following information):

Smartphone (please complete the following information):

Flutter SDK version

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.32.0, on macOS 15.0.1 24A348 darwin-arm64, locale en-GB)
[✓] Android toolchain - develop for Android devices (Android SDK version 36.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 16.0)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2024.2)
[✓] VS Code (version 1.101.2)
[✓] Connected device (7 available)
[✓] Network resources

• No issues found!

Additional context

• This is a regression after migrating from the previous just_audio version (pre-10.x), where the Live Activity showed remaining time and scrub progress correctly.
• If relevant: also using audio_service version 0.18.18. No custom lock-screen integration code beyond the standard setup.