The sonarr/radarr/prowlarr deployments gated startup on Postgres with a
hand-written psql-in-a-shell loop running the postgres:17-alpine image.
Replace it with the purpose-built waitfordb image (v0.1.0), which reads the
same PG* env as a libpq fallback and exits 0 once SELECT 1 succeeds.
- swap image to docker-internal/waitfordb:v0.1.0 (pinned), drop the sh/psql
command (waitfordb is the entrypoint)
- keep the existing PGHOST/PGPORT/PGDATABASE/PGUSER/PGPASSWORD env, name,
and resources unchanged
- add WAITFORDB_TIMEOUT=5m so a stuck DB fails the pod fast, and
WAITFORDB_SSLMODE=disable to match the in-cluster Postgres