fix(migrations): ensure is_system_collection exists before description backfill.

Fresh CI Postgres runs initial-schema without this column (added historically
via scripts); ADD COLUMN IF NOT EXISTS makes the data migration safe on new
and existing envs.

Co-authored-by: Cursor <cursoragent@cursor.com>

migrations/1780378340194_system-collection-description.js

@@ -13,6 +13,9 @@ export const shorthands = undefined;
  */
 export const up = (pgm) => {
   pgm.sql(`
+    ALTER TABLE collections
+    ADD COLUMN IF NOT EXISTS is_system_collection BOOLEAN DEFAULT false;
+
     UPDATE collections
     SET description = 'Automatically syncs with My Collection. This list cannot be deleted or made public.'
     WHERE is_system_collection = true