Add Docker deployment pipeline and site updates

- Dockerfile (multi-stage Next.js standalone build)
- docker-compose.yml for Portainer stack
- Gitea Actions workflow for CI/CD
- Runner container config (Dockerfile.runner + compose)
- next.config.ts: enable standalone output
- Site content and image updates

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

docker-compose.yml

@@ -0,0 +1,10 @@
+services:
+  web:
+    image: micromelon-website:latest
+    container_name: micromelon-web
+    restart: unless-stopped
+    ports:
+      - "3000:3000"
+    environment:
+      - AIRTABLE_API_KEY=${AIRTABLE_API_KEY}
+      - AIRTABLE_BASE_ID=${AIRTABLE_BASE_ID}