Phase 1, step 1 of moving SubscribeStar off gallery-dl onto the native core
ingester (milestone: SubscribeStar native). Mirror of the Patreon ledger:
SubscribeStarSeenMedia (skip already-ingested media on routine walks; recovery
bypasses) and SubscribeStarFailedMedia (dead-letter so persistently-failing
media stops re-burning backfill chunks). Per operator decision, dedicated
per-platform tables (not a generalized shared ledger).
filehash is String(128): a CDN content hash when the URL carries one, else a
synthesized <post_id>:<filename> key. UNIQUE (source_id, filehash) upsert key.
Registered in models/__init__; migration 0054 creates both tables (down 0053).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
