fix: Update nginx config to use dynamic DNS resolution

- Replace upstream blocks with resolver directive
- Use variables for backend addresses to avoid startup errors
- Simplify configuration with single server block
- Add health check endpoint

server/api/node_modules/jest-pnp-resolver/getDefaultResolver.js

@@ -0,0 +1,13 @@
+let defaultResolver;
+
+module.exports = () => {
+  if (!defaultResolver) {
+    try {
+      defaultResolver = require(`jest-resolve/build/defaultResolver`).default;
+    } catch (error) {
+      defaultResolver = require(`jest-resolve/build/default_resolver`).default;
+    }
+  }
+
+  return defaultResolver;
+};