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/css-tree/cjs/syntax/node/String.cjs

@@ -0,0 +1,26 @@
+'use strict';
+
+const string = require('../../utils/string.cjs');
+const types = require('../../tokenizer/types.cjs');
+
+const name = 'String';
+const structure = {
+    value: String
+};
+
+function parse() {
+    return {
+        type: 'String',
+        loc: this.getLocation(this.tokenStart, this.tokenEnd),
+        value: string.decode(this.consume(types.String))
+    };
+}
+
+function generate(node) {
+    this.token(types.String, string.encode(node.value));
+}
+
+exports.generate = generate;
+exports.name = name;
+exports.parse = parse;
+exports.structure = structure;