Redo frontend and dockerfile to use nginx and build in stages based on prod steps in romm

decode.js

@@ -0,0 +1,19 @@
+// Decode a Base64 encoded string received as a query parameter named 'value',
+// and return the decoded value in the response body.
+function decodeBase64(r) {
+  var encodedValue = r.args.value;
+
+  if (!encodedValue) {
+    r.return(400, "Missing 'value' query parameter");
+    return;
+  }
+
+  try {
+    var decodedValue = atob(encodedValue);
+    r.return(200, decodedValue);
+  } catch (e) {
+    r.return(400, "Invalid Base64 encoding");
+  }
+}
+
+export default { decodeBase64 };