/code-review high on S3 — 3 low findings, 2 fixed, 1 no-change:
- _db_reachable() now probes via a throwaway engine with connect_timeout=3, so a
slow/firewalled DATABASE_URL can't hang the whole suite at import (the app engine
has no connect timeout).
- test_plex_facets sets the "configured" gate flag via monkeypatch (auto-restored)
instead of poking state._configured_cache in a manual finally — no leak risk, and
the now-unnecessary mark_configured DB write is dropped.
No change: test_plex_jsonb_normalize copying migration 0060's SQL is deliberate —
migrations must stay self-contained (no app imports) and a shipped migration is
immutable, so there's no real drift to guard against.
Gate: ruff clean; DB lane 176 passed; pure-logic 172 passed / 4 skipped (fast).