docs: update AGENTS.md to Intent Layer spec

Add Purpose & Scope, Entry Points, Dependencies, Traps & Gotchas,
Anti-Patterns sections.

AGENTS.md

@@ -1,10 +1,21 @@
-# batida-landing
+# batida-landing — Intent Node (Root)
 
+## Purpose & Scope
 Marketing/landing page for Batida. Static HTML served via Nginx.
 Separate git repository — self-contained.
 
-## Structure
+**Does:** Serve static HTML landing pages (EN + PT-BR), SEO, Nginx hosting.
+**Does NOT:** Handle user data, run application logic, serve the app (→ batida-web).
 
+## Entry Points
+No build step required. Just serve static files via Nginx.
+
+## Dependencies
+| Depends On | Why |
+|------------|-----|
+| batida-infra | K8s deployment manifests, Dockerfile → Nginx container |
+
+## Structure
 ```
 index.html           → English landing page
 index.pt-br.html     → Portuguese landing page
@@ -17,23 +28,23 @@ sitemap.xml          → SEO sitemap
 k8s/                 → Kubernetes deployment manifests
 ```
 
-## Deployment
-
-Deployed to Kubernetes via `batida-infra`. The Dockerfile copies static HTML into an Nginx container. Manifests in `k8s/` define the deployment.
-
-## Key Facts
-
+## Key Patterns
 - Fully static — no build step, no JavaScript framework
 - Two languages: English and Portuguese (separate HTML files)
 - Nginx handles gzip compression and static caching
 - SEO configured via robots.txt and sitemap.xml
 
+## Traps & Gotchas
+- Both language versions must be updated in sync — forgetting one leaves stale content
+- No hot reload or dev server — edit HTML, refresh browser
+
+## Anti-Patterns
+- Never add server-side logic or build tools — pure static HTML
+- Never commit secrets or environment-specific values
+- Never add JavaScript frameworks — keep it static
+
 ## Boundaries
 
 ### Always
 - Keep both language versions in sync when updating content
 - Test HTML renders correctly in browser before committing
-
-### Never
-- Never add server-side logic or build tools — pure static HTML
-- Never commit secrets or environment-specific values