chore: project cleanup - remove unused dependencies and routes

- Remove unused axios package and 22 dependencies
- Fix 2 moderate npm security vulnerabilities
- Remove test route /test-zweite-db (no longer needed)
- Remove unused DB facade import from routes/web.php

This cleanup reduces bundle size and improves maintainability.

package.json

@@ -8,7 +8,6 @@
     "dependencies": {
         "@tailwindcss/vite": "^4.1.11",
         "autoprefixer": "^10.4.20",
-        "axios": "^1.7.4",
         "concurrently": "^9.0.1",
         "laravel-vite-plugin": "^2.0",
         "tailwindcss": "^4.0.7",