The check_compatibility(false) method was added in the previous commit
but does not exist in sqlx 0.8.x used by sea-orm 2.0. The warning
"Failed to obtain server version" is cosmetic and does not affect
functionality.
Cloud-managed PostgreSQL variants (PolarDB, CockroachDB, etc.) may
not return a standard version string, causing:
"Failed to obtain server version. Unable to check client-server
compatibility."
Setting check_compatibility(false) on both writer and reader
connections silences this harmless warning.
CNPG's cluster-ro service already handles load balancing and failover,
so the application-level Vec + random_range is redundant.
- db_read: Vec<DatabaseConnection> → Option<DatabaseConnection>
- database_read_replicas returns Option<String> instead of Vec<String>
- health checks now explicitly ping both writer() and reader()
- remove unused rand dependency from libs/db
