docs: move working notes into docs-cms

AGENTS.md

@@ -0,0 +1,9 @@
+# Agent Instructions
+
+Use `docs-cms/` as durable project memory. Read relevant ADRs, RFCs, PRDs, and memos before changing architecture, validation, schemas, templates, release process, or agent workflow guidance.
+
+Docuchango maintains its own `docs-cms/`. Product decisions and durable maintenance knowledge belong there. `examples/docs-cms/` is sample user content, not authoritative project memory.
+
+After docs-cms edits, run `docuchango validate` and summarize remaining manual issues.
+
+Do not mark agent-authored architectural decisions `Accepted` without explicit user approval. Use `Proposed` or a memo for inferred content.