feat: add AGENTS.md for all packages and apps (9 files)

apps/cms/AGENTS.md

@@ -0,0 +1,18 @@
+# apps/cms — Payload CMS Admin Shell
+
+Thin Next.js shell that imports config from `@repo/cms-core` and serves the Payload admin panel. Contains almost no custom code.
+
+## Rules
+
+- All collections, hooks, globals, and payload.config.ts live in `@repo/cms-core`
+- This app only contains Next.js routing boilerplate for the admin panel
+- Import `@payload-config` which resolves to `@repo/cms-core/src/payload.config.ts`
+- NEVER import from `@repo/core/infrastructure`
+
+## Development
+
+```bash
+pnpm dev --filter @repo/cms  # Starts on port 3001
+```
+
+Requires PostgreSQL running (via `docker compose up postgres`).