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/resolve/lib/caller.js

@@ -0,0 +1,12 @@
+'use strict';
+
+var $Error = require('es-errors');
+
+module.exports = function () {
+    // see https://code.google.com/p/v8/wiki/JavaScriptStackTraceApi
+    var origPrepareStackTrace = $Error.prepareStackTrace;
+    $Error.prepareStackTrace = function (_, stack) { return stack; };
+    var stack = (new $Error()).stack;
+    $Error.prepareStackTrace = origPrepareStackTrace;
+    return stack[2].getFileName();
+};