Establish Railiance Fabric graph model

examples/declarations/valid/binding-flex-auth-openbao.yaml

@@ -0,0 +1,23 @@
+apiVersion: railiance.fabric/v1alpha1
+kind: BindingAssertion
+metadata:
+  id: flex-auth.api.runtime-secrets-to-openbao
+  name: flex-auth runtime secrets binding
+  owner: flex-auth
+  repo: flex-auth
+  domain: railiance
+  source_links:
+    - label: Runtime secrets binding note
+      path: docs/runtime-secrets.md
+spec:
+  lifecycle: active
+  environments: [dev, staging, prod]
+  dependency_id: flex-auth.api.needs-runtime-secrets
+  provider_capability_id: railiance-platform.openbao.runtime-secrets
+  provider_interface_id: railiance-platform.openbao.kv-v2
+  status: exact
+  rationale: flex-auth uses the OpenBao KV v2 mount as its runtime secrets provider.
+  compatibility:
+    version: v1
+    compatible_with:
+      - railiance-platform.openbao.kv-v2