Initialize project and update portal port configuration

Set default portal port to 8081, fix Dart build issue in cart screen, and update setup documentation.

Co-Authored-By: Oz <oz-agent@warp.dev>

docker/nginx/default.conf

@@ -0,0 +1,16 @@
+server {
+    listen       80;
+    server_name  _;
+
+    root   /usr/share/nginx/html;
+    index  index.html;
+
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+
+    location ~* \.(?:js|css|png|jpg|jpeg|gif|svg|ico|woff2?)$ {
+        expires 7d;
+        add_header Cache-Control "public";
+    }
+}