Mockito-helper fixture builders for the Culvert framework contracts. Consumers use these helpers to mock SecretProvider, Warehouse, BlobStore, JobControlRepository, and FinOpsSink in their own unit tests without repeating the Mockito + when(...).thenReturn(...) boilerplate. Sprint-2 deliverable (issue #26). Note: Mockito and AssertJ are COMPILE-scope deps here (overriding the parent's test scope). This module IS a test-helper library — its ...