Rebuild on the Bennett platform: Spring Boot + Vite/React

Same site — glass header, bento grid, hero drift, dark mode — with three things fixed
on the way:

- Tailwind and lucide came from CDNs on every page load, and the fonts from Google. All
  are now built in or self-hosted, so the site owes nothing to third parties at runtime.
- The hero and bento photographs were hot-linked from Unsplash. They are re-encoded to
  webp and served from the MinIO bucket with a year-long cache.
- The ministries and labs were hard-coded in the markup, so launching a ministry meant
  editing HTML. They now come from /api/network.

The mobile menu button also opens something now; it did nothing before.

.dockerignore

@@ -1,4 +1,7 @@
-.git
-Dockerfile
-.dockerignore
-README.md
+target/
+frontend/node_modules/
+frontend/dist/
+.git/
+.idea/
+*.iml
+.vscode/