diff --git a/backend/migrations/034_cached_rfc_meta.sql b/backend/migrations/034_cached_rfc_meta.sql
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+-- §22.4a SLICE-3 — configurable collection metadata: cache per-entry values.
+--
+-- Faceted filtering (§5.1) needs each entry's metadata values (priority, custom
+-- enum/tags fields) to compute facet counts and honour filter params. Today the
+-- mirror keeps only `tags_json` + the lifecycle columns and drops `Entry.extra`,
+-- so a declared field's values are unrecoverable. This column persists the full
+-- per-entry metadata mapping (`metadata.metadata_dict(entry)`, known keys +
+-- extra, never the body) as JSON, so `app/facets.py` can read any declared
+-- field uniformly. Additive + nullable — no rebuild. NULL = not yet re-ingested
+-- (the reconciler/webhook fills it on the next sweep) → that entry contributes
+-- no facet values until then. SLICE-4/5 edit panels read the same column.
+ALTER TABLE cached_rfcs ADD COLUMN meta_json TEXT;