Migrate Callers Then Delete Legacy APIs When we decide a new API is the right design, migrate callers and remove the old API in the same refactor wave instead of preserving compatibility layers. Rule: - Do not keep legacy API paths alive only because internal callers still exist - Inventory callers, migrate them, and delete the old API immediately - Treat temporary adapters as exceptional and time-boxed, not default architecture - Update tests to assert the new contract, and delete tests that only protect pre-refactor implementation details When this applies: - No external users depend on bac…