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/selectors/index.js

@@ -0,0 +1,21 @@
+"use strict";
+
+exports.__esModule = true;
+var _types = require("./types");
+Object.keys(_types).forEach(function (key) {
+  if (key === "default" || key === "__esModule") return;
+  if (key in exports && exports[key] === _types[key]) return;
+  exports[key] = _types[key];
+});
+var _constructors = require("./constructors");
+Object.keys(_constructors).forEach(function (key) {
+  if (key === "default" || key === "__esModule") return;
+  if (key in exports && exports[key] === _constructors[key]) return;
+  exports[key] = _constructors[key];
+});
+var _guards = require("./guards");
+Object.keys(_guards).forEach(function (key) {
+  if (key === "default" || key === "__esModule") return;
+  if (key in exports && exports[key] === _guards[key]) return;
+  exports[key] = _guards[key];
+});