docs(api): approve merchant API contract

docs/API-SPEC.md

@@ -1,6 +1,6 @@
 # Merchant Analytics API Capability Spec
 
-- Status: Draft for review — implementation not yet authorized
+- Status: Approved specification — implementation not yet authorized
 - Capability: Merchant API
 - Depends on: Approved Identity, Data Foundation, and Analytics Engine specifications
 - Interface source of truth: `docs/openapi.yaml`
@@ -282,7 +282,7 @@ Correlate `requestId`, authenticated user/merchant internal ids, run id, section
 
 ## Remaining product questions
 
-None. Final approval of this complete capability spec and its OpenAPI contract remains the SDD gate before implementation planning.
+None.
 
 ## Standards references