feat(app): add prerender, self-hosted fonts and privacy page

Fonts come from npm, not Google, so no third-party font requests.
Pages are prerendered at build time; browser-only code is guarded.
nginx serves per-route HTML, a real 404 and gzip.

package.json

@@ -9,7 +9,8 @@
     "test": "ng test --watch=false",
     "lint": "ng lint && npm run assets:check",
     "i18n:check": "node scripts/check-i18n.mjs",
-    "assets:check": "node scripts/check-assets.mjs"
+    "assets:check": "node scripts/check-assets.mjs",
+    "prerender:check": "node scripts/check-prerender.mjs"
   },
   "private": true,
   "dependencies": {
@@ -22,11 +23,15 @@
     "@angular/forms": "~22.2.2",
     "@angular/material": "~22.2.2",
     "@angular/platform-browser": "~22.2.2",
+    "@angular/platform-server": "~22.2.2",
     "@angular/router": "~22.2.2",
     "@angular/service-worker": "~22.2.2",
+    "@angular/ssr": "~22.2.2",
     "@babylonjs/core": "^9.30.0",
+    "@fontsource/roboto": "^5.3.0",
     "@ngx-translate/core": "^18.0.0",
     "@ngx-translate/http-loader": "^18.0.0",
+    "material-icons": "^1.13.14",
     "rxjs": "~7.8.2",
     "swiper": "^14.3.0",
     "tslib": "~2.8.1"