Fix backfiller metric leak: use RAII guard for BACKFILLER_REPOS_RUNNING

Add PDS host banning to rsky-relay with admin API

Fix relay crash-loop: replace unreachable!() with graceful skip in MST validator and DID resolver

Increase LMDB map size from 1TB to 4TB

Skip regex URI validation in backfiller hot path

Replace batch-and-barrier backfiller with continuous channel pipeline

Fix backfiller: bulk Fjall dequeue, batch LMDB enqueue, PDS endpoint cache

Fix relay HTTP endpoints returning 502 via Caddy

Fix profile_agg count inflation on replayed events, add priority backfill tooling

Fix relay PLC resolution for migrated users

Merge feedgen-pinned-post: add pinned post support and non-fatal notification inserts

Add JSON validation and null byte stripping to record indexing

Set hasThreadGate/hasPostGate flags on post table during gate indexing

Make label_sync negation-only: skip positive labels, never insert rows

Fix label_sync: install rustls crypto provider on startup