Fix cross-team asset 401 and stale label associations in QC script

[salmanfarisvp]

Summary

• Root cause: GET /v4/assets returns cross-team shared assets that the token's RLS policy blocks on insert (42501 insufficient_privilege → HTTP 401). The script was randomly picking these assets, causing consistent failures at POST /v4/playlist-items.
• Secondary issue: delete_playlist() was not removing labels/playlists associations before deleting a playlist, leaving stale rows that caused POST /v4/labels/playlists to fail on subsequent runs.

Changes

Fix cross-team asset 401

• Added get_team_id() helper that fetches the current account's team ID via GET /v4/labels?type=eq.all-screens
• Updated get_ten_random_assets() to accept team_id and filter the assets query with team_id=eq.{team_id}, ensuring only same-team assets (which the token can insert) are selected

Fix stale label associations

• Updated delete_playlist() to explicitly call DELETE /v4/labels/playlists?playlist_id=eq.{id} before deleting playlist items and the playlist itself
• Added resolution=ignore-duplicates to the Prefer header in POST /v4/labels/playlists as a safety net

Better observability

• Added progress logging (Playlist created, Adding assets to playlist..., Assigning playlist to all screens...) so future failures are immediately pinpointed to the exact step
• Renamed the catch-all error message from "Unable to create playlist" to "QC playlist setup failed" since it covers asset-adding and label-linking failures too

API Issues Raised

These are workarounds for underlying API inconsistencies that have been raised as an engineering ticket:

1. GET /v4/assets should not return assets the token cannot write — or should clearly mark them as read-only/cross-team
2. RLS/privilege violations should return 403 Forbidden, not 401 Unauthorized
3. DELETE /v4/playlists should cascade-delete labels/playlists rows

Test plan

• Ran locally — script completed successfully end-to-end (exit code 0)
• Verified delete_playlist() cleans up label associations on each run
• Verified get_ten_random_assets() only returns same-team assets