Player: opening the PWA no longer auto-plays when the user had paused. Pausing via
the media notification while backgrounded routes through togglePlay, which now sets
S._userPaused; _onForeground only auto-resumes an INVOLUNTARY background stop
(_wasPlayingBeforeHide && !_userPaused). playCurrent clears the flag on a new track.
Involuntary-stop/freeze recovery on foreground is preserved.
Stats modal: no more small→big flash when switching period/tab — the body keeps a
stable min-height and retains its current content until the new data arrives (only
the first open shows 'Lade…'); a per-request token drops out-of-order responses.
SW cache -> ns-v71.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>