feat(db): add migration 0008 for scrobble (users LB columns + scrobble_queue table)

internal/db/migrations/0008_scrobble.down.sql

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+DROP TABLE IF EXISTS scrobble_queue;
+ALTER TABLE users DROP COLUMN IF EXISTS listenbrainz_enabled;
+ALTER TABLE users DROP COLUMN IF EXISTS listenbrainz_token;

internal/db/migrations/0008_scrobble.up.sql

@@ -0,0 +1,26 @@
+-- M4a: outbound ListenBrainz scrobble worker.
+-- Per-user LB config (plaintext token; users rotate via /settings if leaked).
+-- scrobble_queue is a work list, not a log: successfully-sent rows are
+-- DELETEd by the worker (the canonical record stays in play_events.scrobbled_at
+-- via M2's column). Only `pending` and `failed` states exist.
+
+ALTER TABLE users
+    ADD COLUMN listenbrainz_token   TEXT NULL,
+    ADD COLUMN listenbrainz_enabled BOOLEAN NOT NULL DEFAULT FALSE;
+
+CREATE TABLE scrobble_queue (
+    id               uuid        PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id          uuid        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    play_event_id    uuid        NOT NULL REFERENCES play_events(id) ON DELETE CASCADE,
+    status           TEXT        NOT NULL CHECK (status IN ('pending', 'failed')),
+    attempts         INTEGER     NOT NULL DEFAULT 0,
+    next_attempt_at  timestamptz NOT NULL DEFAULT now(),
+    last_error       TEXT        NULL,
+    enqueued_at      timestamptz NOT NULL DEFAULT now(),
+    UNIQUE (play_event_id)
+);
+
+-- Hot path for the worker's per-tick query.
+CREATE INDEX scrobble_queue_pending_idx
+    ON scrobble_queue (next_attempt_at)
+    WHERE status = 'pending';