refactor: consolidate public-web port to 8080 and add API proxy configuration

Remove backend port exposure and change public-web from port 8082 to 8080. Add backend dependency to public-web service. Remove public-web dependency from nginx service. Add /api/ location block to public-web nginx config with proxy_pass to backend:8080 and proxy headers for Host, X-Real-IP, X-Forwarded-For and X-Forwarded-Proto.

public-web/nginx.conf

@@ -4,6 +4,14 @@ server {
     root /usr/share/nginx/html;
     index index.html;
 
+    location /api/ {
+        proxy_pass http://backend:8080;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+    }
+
     location / {
         try_files $uri /index.html;
     }