beatify

Recurring backfill job (#1289) that systematically fills missing per-provider track URIs across Beatify playlists. For every song that has a Spotify `uri` but is missing `uri_apple_music` / `uri_tidal` / `uri_deezer`, it resolves the gaps via the keyless Odesli / song.link API (Tidal + Deezer reliably, Apple Music best-effort) with a verifying Deezer-ISRC fallback; missing `uri_youtube_music` is filled via the YouTube Data API behind a resume-cursor + daily quota budget. Rate-limit safe (Odesli throttle + 429 backoff, YouTube daily budget). Emits a per-playlist Markdown coverage report. Use this skill whenever the user asks to backfill provider URIs, fill missing Apple/Tidal/ Deezer/YouTube links, improve provider coverage, run the URI backfill, or check per-playlist provider coverage.