Drives isPipEnabled on Android (floating pipStatus polled while fullscreen)
so the Flutter caption overlay hides in PiP, and suppresses native
embedded/sidecar captions; the prior selection is restored on exit.
iOS unchanged.

Also brings git in sync with the 1.2.0 subtitle e-learning work that was
published from an uncommitted tree.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FgKo3tRLn8XMJJDt68wbFa