feat(frontend): add API client, layout, and routing

- Create Axios-based API client with sources, jobs, and dashboard endpoints
- Add responsive Layout component with navigation sidebar
- Set up React Router with Dashboard, Backups, and Settings routes
- Configure TanStack Query provider with default options
- Use lucide-react for navigation icons

frontend/node_modules/postcss-selector-parser/dist/util/stripComments.js

@@ -0,0 +1,21 @@
+"use strict";
+
+exports.__esModule = true;
+exports["default"] = stripComments;
+function stripComments(str) {
+  var s = "";
+  var commentStart = str.indexOf("/*");
+  var lastEnd = 0;
+  while (commentStart >= 0) {
+    s = s + str.slice(lastEnd, commentStart);
+    var commentEnd = str.indexOf("*/", commentStart + 2);
+    if (commentEnd < 0) {
+      return s;
+    }
+    lastEnd = commentEnd + 2;
+    commentStart = str.indexOf("/*", lastEnd);
+  }
+  s = s + str.slice(lastEnd);
+  return s;
+}
+module.exports = exports.default;