Add revision history log and music files ZIP backup

models.py

@@ -55,6 +55,21 @@ CREATE TABLE IF NOT EXISTS requests (
 
 CREATE INDEX IF NOT EXISTS idx_requests_status ON requests(status);
 CREATE INDEX IF NOT EXISTS idx_requests_token ON requests(player_token);
+
+CREATE TABLE IF NOT EXISTS revision_history (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    request_id INTEGER NOT NULL,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    revision_count INTEGER NOT NULL,
+    note TEXT,
+    old_song_a_path TEXT,
+    old_song_b_path TEXT,
+    new_song_a_path TEXT,
+    new_song_b_path TEXT,
+    FOREIGN KEY (request_id) REFERENCES requests(id) ON DELETE CASCADE
+);
+
+CREATE INDEX IF NOT EXISTS idx_revision_history_request ON revision_history(request_id);
 """
 
 
@@ -168,6 +183,28 @@ def delete_request(request_id):
     db.commit()
 
 
+def log_revision(request_id, revision_count, note, old_a=None, old_b=None, new_a=None, new_b=None):
+    """Record a revision event in the revision_history table."""
+    db = get_db()
+    db.execute(
+        """INSERT INTO revision_history
+           (request_id, revision_count, note, old_song_a_path, old_song_b_path, new_song_a_path, new_song_b_path)
+           VALUES (?, ?, ?, ?, ?, ?, ?)""",
+        (request_id, revision_count, note, old_a, old_b, new_a, new_b)
+    )
+    db.commit()
+
+
+def list_revision_history(request_id):
+    """Return all revision history rows for a request, oldest first."""
+    db = get_db()
+    rows = db.execute(
+        'SELECT * FROM revision_history WHERE request_id = ? ORDER BY created_at ASC',
+        (request_id,)
+    ).fetchall()
+    return [dict(r) for r in rows]
+
+
 def reset_all_requests():
     """Delete every row in the requests table and reset id auto-increment."""
     db = get_db()