Two replicas racing prisma migrate deploy can deadlock, and the loser dies
mid CREATE INDEX CONCURRENTLY, leaving the index INVALID. The retried
migration's IF NOT EXISTS then skips it, so the planner never uses it.
After migrations succeed, look for INVALID indexes on LiteLLM tables and
have one replica (advisory try-lock) REINDEX INDEX CONCURRENTLY each of
them, dropping _ccnew/_ccold leftovers of an interrupted rebuild instead.
The repair never blocks startup: a failed rebuild is logged and retried
on the next boot. Also encode DATABASE_URL query values with quote instead
of quote_plus so options=-c%20... reaches psycopg intact.
