Redo frontend and dockerfile to use nginx and build in stages based on prod steps in romm

default.conf

@@ -0,0 +1,73 @@
+# Helper to get scheme regardless if we are behind a proxy or not
+map $http_x_forwarded_proto $forwardscheme {
+    default $scheme;
+    https https;
+}
+
+# COEP and COOP headers for cross-origin isolation, which are set only for the
+# EmulatorJS player path, to enable SharedArrayBuffer support, which is needed
+# for multi-threaded cores.
+map $request_uri $coep_header {
+    default        "";
+    ~^/rom/.*/ejs$ "require-corp";
+}
+map $request_uri $coop_header {
+    default        "";
+    ~^/rom/.*/ejs$ "same-origin";
+}
+
+server {
+    root /app/code/frontend;
+    listen 3000;
+    listen [::]:3000;
+
+    proxy_set_header Host $http_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 $forwardscheme;
+
+    location / {
+        try_files $uri $uri/ /index.html;
+        proxy_redirect off;
+        add_header Access-Control-Allow-Origin *;
+        add_header Access-Control-Allow-Methods *;
+        add_header Access-Control-Allow-Headers *;
+        add_header Cross-Origin-Embedder-Policy $coep_header;
+        add_header Cross-Origin-Opener-Policy $coop_header;
+    }
+
+    # Static files
+    location /assets {
+        try_files $uri $uri/ =404;
+    }
+
+    # OpenAPI for swagger and redoc
+    location /openapi.json {
+        proxy_pass http://backend_server;
+    }
+
+    # Backend api calls
+    location /api {
+        proxy_pass http://backend_server;
+        proxy_request_buffering off;
+        proxy_buffering off;
+    }
+    location ~ ^/(ws|netplay) {
+        proxy_pass http://backend_server;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
+    }
+
+    # Internally redirect download requests
+    location /library/ {
+        internal;
+        alias "/app/data/library/";
+    }
+
+    # Internal decoding endpoint, used to decode base64 encoded data
+    location /decode {
+        internal;
+        js_content decode.decodeBase64;
+    }
+}