Origin Ghost Player v0.3.0

Two builds now, same code, different spoofed identity — pick whichever native widget you prefer:

• origin-ghost-player-kugou-0.3.0.apk — the original, most-tested identity.
• origin-ghost-player-luna-0.3.0.apk — Luna Music's identity gets a noticeably bigger
  lockscreen widget (more room for album art and text) and surfaces karaoke support in
  OriginPlayer that Kugou's doesn't.

Both are signed with the same key (fingerprint matches origin-isle's and each other) and can be
installed side by side, since they're different package identities.

Other changes

• More informative first-run screen — explains why notification access is needed, and adds a
  button to request unrestricted background running (so OriginOS is less likely to kill the
  bridge while your screen is off). Also fixes content drawing behind the status bar under
  edge-to-edge (targetSdk 36).
• Less flickering between album art when switching source apps — source tracking is now
  sticky instead of re-evaluating "which session is playing" from scratch every second.
• More resilient to long background stretches — if another app holds real audio output for an
  extended period (observed: ~10 minutes), the bridge process could get killed under memory
  pressure without ever being swiped away, so the existing swipe-away recovery never engaged. A
  periodic health-check alarm now catches this case too.

See docs/DEV.md for details.