Function assert_config_schema_valid 

pub fn assert_config_schema_valid<C: HasConfigSchema + ?Sized>(connector: &C)

Check 1. Assert the connector’s config_schema() is a structurally valid JSON Schema that round-trips through serde_json.

Panics (fails the test) on: a non-object schema, a schema with no recognized schema shape, a non-object properties, or a serialize→parse→serialize that is not stable.