fix: Reduce aggressive browser caching for static assets

Changed cache expiry from 1 year to 1 hour and removed immutable flag
to allow browser cache updates. The 1-year cache was preventing logo
updates from being visible without clearing browser cache.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

nginx-site.conf

@@ -10,10 +10,10 @@ server {
     gzip_types text/css application/javascript image/jpeg image/png;
     gzip_min_length 1000;
 
-    # Cache static assets
+    # Cache static assets (reduced for development)
     location ~* \.(jpg|jpeg|png|gif|ico|css|js)$ {
-        expires 1y;
-        add_header Cache-Control "public, immutable";
+        expires 1h;
+        add_header Cache-Control "public, max-age=3600";
     }
 
     # Main location