Start Core Hub FastAPI replacement foundation

contracts/README.md

@@ -0,0 +1,14 @@
+# Core Hub Contract Artifacts
+
+This directory contains the implementation-neutral contract artifacts consumed by the Core Hub runtime and future adapters.
+
+- `schemas/` - JSON Schema contracts
+- `catalogs/` - seed event/widget/policy catalogs
+- `fixtures/` - production-safe compatibility examples
+- `openapi/` - generated OpenAPI snapshots
+
+Regenerate OpenAPI after route changes:
+
+```bash
+make openapi
+```