Add performance optimizations: gzip, cache headers, WOFF2 fonts, lazy loading

Enable gzip compression in nginx, add cache-control headers for static assets,
convert fonts to WOFF2 with font-display swap, preload fonts, add lazy loading
to below-fold images, and remove unused font files.

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

nginx/nginx_dev.conf.template

@@ -24,6 +24,22 @@ http {
         text/javascript mjs;
     }
 
+    gzip on;
+    gzip_vary on;
+    gzip_proxied any;
+    gzip_comp_level 6;
+    gzip_min_length 256;
+    gzip_types
+        text/plain
+        text/css
+        text/javascript
+        application/javascript
+        application/json
+        application/xml
+        image/svg+xml
+        font/woff2
+        application/font-woff2;
+
     server {
         listen 80;
         server_name $DOMAIN www.$DOMAIN;