fix(karrot): fix nginx DNS resolver for Kubernetes and add README

The karrot-frontend nginx template hardcodes Docker's DNS resolver
(127.0.0.11) which doesn't exist in Kubernetes. Added a ConfigMap to
override the template, removing the Docker DNS resolver by using a
direct proxy_pass with no nginx variable (which would force runtime
resolution). Also adds a README with usage instructions.

Documents lessons learned in ADDING-APPS-NOTES.md:
- Note 24: nginx Docker DNS resolver doesn't work in Kubernetes; any
  nginx variable in proxy_pass (including $request_uri) forces runtime
  DNS resolution requiring a resolver directive
- Note 25: ConfigMap changes don't restart pods; subPath mounts never
  auto-update; always follow with kubectl rollout restart
- Note 26: includeSelectors mismatch affects every deployment in an
  app — check all endpoints, not just the web-facing one

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

karrot/versions/1/README.md

@@ -0,0 +1,35 @@
+# Karrot
+
+Karrot is a community platform for sharing resources, coordinating food-saving activities, and organizing volunteers. Groups can manage pickups, track saved food, and communicate through a shared feed.
+
+## Dependencies
+
+- **PostgreSQL** - Database for storing groups, users, and activity data
+- **SMTP** - For account verification and notifications
+
+## Configuration
+
+Key settings in `config.yaml`:
+
+- **domain** - Where Karrot will be accessible (default: `karrot.{your-cloud-domain}`)
+- **storage** - Persistent volume size for uploaded files (default: `2Gi`)
+- **redis.host** - Redis instance for caching and background jobs (default: app-local `karrot-redis`)
+- **smtp** - Email settings inherited from your Wild Cloud SMTP service
+
+## First-Time Setup
+
+1. Add and deploy the app:
+   ```bash
+   wild app add karrot
+   wild app deploy karrot
+   ```
+
+2. Visit `https://karrot.{your-cloud-domain}` and register an account. The first user to register becomes the site admin.
+
+3. Log in and create your first group to start coordinating.
+
+## Notes
+
+- Karrot supports federation — groups can connect with other Karrot instances
+- The `secretKey` and `dbPassword` are auto-generated in `secrets.yaml`
+- Uploaded files (photos, attachments) are stored in the persistent volume and shared between the frontend and backend pods