Back goes to the previous song, or asks the room to

[madeofpendletonwool]

Back used to only restart the song, so there was no way to hear the last one again.

What back does now

• After the first 3 seconds of a song, back restarts it, as before.
• Within the first 3 seconds (for example, pressing back twice), it plays the previous song again. The phone lock-screen control works the same way.
• The song that was interrupted goes to the front of the queue and plays next, from the start. Its unfinished play is deleted, so it doesn't count as a skip in stats or in the DJ's picks, and its owner doesn't lose their turn. Going back several times puts each interrupted song back, the most recent first.
• Going back ends the current song, so it uses the skip permission. In a room that votes on skips, anyone except the owner starts a vote, which reuses the "play now" vote ("bob wants to go back to Song", with a Go back button). The request lapses if the song changes. Guests can't start a vote to go back.

Changes

• API: new previous playback action. PlayNowVote gains back and item, since the song isn't in the queue.
• Migration 00024: adds queue_items.resume_at. Songs with it set play ahead of the fair order. Moving or removing a song clears it.
• Engine: previousCommand, previous and goBack. Play-now votes can now settle as a go-back.
• Web: back-button logic in use-room-controls, the lock-screen handler in speaker.ts, and the vote prompt in play-now-request.
• Docs: the playback-engine design doc (ADR 0003) and player-mode.md.

Testing

• New tests: TestPrevious and TestPreviousVote.
• go test -race ./..., golangci-lint, and the web typecheck, lint and tests all pass.
• Not yet tried by hand in a real room.

🤖 Generated with Claude Code