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/index.d.ts

@@ -0,0 +1,10 @@
+type JestResolverOptions = {
+  basedir: string;
+  defaultResolver: (request: string, opts: any) => string,
+  extensions?: Array<string>,
+};
+
+export default function resolve(
+  request: string,
+  options: JestResolverOptions,
+): string;