Add stems_link support for Pingvin-Share-X delivery

models.py

@@ -49,7 +49,8 @@ CREATE TABLE IF NOT EXISTS requests (
     player_token TEXT NOT NULL UNIQUE,
     revision_count INTEGER DEFAULT 0,
     revision_note TEXT,
-    operator_notes TEXT
+    operator_notes TEXT,
+    stems_link TEXT
 );
 
 CREATE INDEX IF NOT EXISTS idx_requests_status ON requests(status);