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/undefsafe/example.js

@@ -0,0 +1,14 @@
+var undefsafe = require('undefsafe');
+
+var object = {
+  a: {
+    b: {
+      c: 1,
+      d: [1, 2, 3],
+      e: 'remy'
+    }
+  }
+};
+
+console.log(undefsafe(object, 'a.b.e')); // "remy"
+console.log(undefsafe(object, 'a.b.not.found')); // undefined