docs(adr): add glossary pages and ADR baseline structure

docs/public-api/glossary.md

@@ -0,0 +1,43 @@
+# Public API Glossary
+
+## Scope
+
+Baseline terms for future public API design and integration discussions.
+
+## Terms
+
+### Public API
+
+Externally consumable endpoints intended for non-admin clients.
+
+### Resource
+
+Entity exposed by an API endpoint (for example: `page`, `media`, `news`).
+
+### Contract
+
+The stable request/response schema for an endpoint version.
+
+### Version
+
+Compatibility boundary for API contracts (for example: `v1`).
+
+### Authentication
+
+Identity verification mechanism for protected API routes.
+
+### Authorization
+
+Permission check determining whether an authenticated actor can access a resource/action.
+
+### Pagination
+
+Mechanism for splitting large result sets across requests.
+
+### Idempotency
+
+Property where repeating a request does not change final state beyond the first successful call.
+
+### Rate Limit
+
+Request threshold policy applied per consumer/time window.

docs/public-api/index.md

@@ -11,6 +11,11 @@ No stable public API surface is documented yet.
 - Add API docs when real endpoints are implemented and versioned
 - Use OpenAPI as source of truth for endpoint reference
 - Keep integration guides and authentication examples here
+- Use glossary terms consistently across API specs and guides
+
+## Reference
+
+- [Public API Glossary](/public-api/glossary)
 
 ## Notes