Harden RC7 API response contracts

docs/RC_ROADMAP_BELGIUM_NORTH_SEA.md

@@ -150,8 +150,8 @@ editions and licences must still pass source-specific probes before activation.
 | RC-4 | complete | national/maritime scope and provider coverage contracts |
 | RC-5 | complete | deployment, secrets, configuration, fresh install and rollback |
 | RC-6 | complete | complete CI, dependency and supply-chain gates |
-| RC-7 | in progress | critical API envelope typing and contract validation |
-| RC-8 | pending | frontend and browser E2E release journeys |
+| RC-7 | complete | critical API envelope typing and contract validation |
+| RC-8 | in progress | frontend and browser E2E release journeys |
 | RC-9 | pending | loading, accessibility and performance hardening |
 | RC-10 | pending | retention, cleanup and national data operations |
 | RC-11 | pending | final package, upgrade proof, release tag and handoff |
@@ -405,6 +405,13 @@ UID 999.
 
 ## RC-7 - Critical API contract hardening
 
+**State: complete.** All successful JSON routes now publish concrete OpenAPI
+response schemas. The contract audit covers 124 implemented routes and 228
+component schemas; the eight non-envelope operations are the three health
+probes, four persisted PNG responses and the export download. Readiness passed
+with 1,008 backend tests, frontend typecheck/build, one Alembic head and
+offline migration SQL generation.
+
 ### Work
 
 - replace `response_model=dict` first on health, projects, areas, datasets,