[TerribleTurtle]

Summary

• stop the sleep timer shake sensor and widget stats timer when playback pauses in the background
• stop the 30s local server probe when a book finishes on its own in the background
• pause idle Chromecast route discovery when backgrounded without an active or reconnecting session

Why

Following up on 35005349: if you leave the app while listening and then pause from headphones or the lock screen, or let a book finish, these kept running overnight. The background check only looked at whether playback was already paused at the moment you left the app. Confirmed the shake sensor and Cast discovery shut off in dumpsys on my Pixel.

Before / after trace

Before: background while playing -> pause from headset -> shake sensor, stats timer, probe, Cast discovery stay on
After:  pause or book end while backgrounded -> all four stop; they come back on resume or when the app reopens