Lock Screen Now Reflects Actual Playback State
Restructured the playback control path so the lock screen and Now Playing always reflect the true audio state.
Discrepancies between lock screen playback information and actual audio state—such as showing a paused indicator while audio is playing, or retaining previous track metadata after a transition—do not surface in feature checklists but directly degrade playback reliability.
This update restructures the control path so that Now Playing metadata and lock screen remote controls consistently reflect actual playback state. Audio, video, and currently mounted content are unified into a single source, ensuring that all externally exposed state originates from one place. The presentation layer renders playback state as-is; state authority remains exclusively with the playback owner.
As a result, play and pause actions from the lock screen take effect immediately in audio output, and the displayed track information always matches what is currently playing.