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>

.gitea/workflows/deploy.yml

@@ -0,0 +1,24 @@
+name: Build and Deploy
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  deploy:
+    runs-on: self-hosted
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Build Docker image
+        run: |
+          SHA=$(echo "${{ gitea.sha }}" | cut -c1-7)
+          docker build -t micromelon-website:$SHA -t micromelon-website:latest .
+
+      - name: Restart container
+        run: docker compose -f /opt/micromelon/docker-compose.yml up -d
+
+      - name: Prune old images
+        run: docker image prune -f