feat: define workspace diagnostic contracts

backend/test/workspace-runtime-renderer.test.ts

@@ -16,6 +16,8 @@ dwh:
 semantic_index:
   vector_store:
     engine: pgvector
+    database: postgres
+    schema: vectors
     collection: clinical_documents
     dimensions: 768
     distance: cosine
@@ -81,7 +83,8 @@ test("renders a direct PostgreSQL binding to the legacy harness shape", () => {
     },
     vector_db: {
       host: "vector.internal",
-      schema: "datawarehouse",
+      database: "postgres",
+      schema: "vectors",
       password_file: "/run/secrets/vector-password",
       ssl_ca_file: "/run/secrets/vector-ca.pem",
     },