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/lib/syntax/node/MediaQuery.js

@@ -0,0 +1,60 @@
+import {
+    WhiteSpace,
+    Comment,
+    Ident,
+    LeftParenthesis
+} from '../../tokenizer/index.js';
+
+export const name = 'MediaQuery';
+export const structure = {
+    children: [[
+        'Identifier',
+        'MediaFeature',
+        'WhiteSpace'
+    ]]
+};
+
+export function parse() {
+    const children = this.createList();
+    let child = null;
+
+    this.skipSC();
+
+    scan:
+    while (!this.eof) {
+        switch (this.tokenType) {
+            case Comment:
+            case WhiteSpace:
+                this.next();
+                continue;
+
+            case Ident:
+                child = this.Identifier();
+                break;
+
+            case LeftParenthesis:
+                child = this.MediaFeature();
+                break;
+
+            default:
+                break scan;
+        }
+
+        children.push(child);
+    }
+
+    if (child === null) {
+        this.error('Identifier or parenthesis is expected');
+    }
+
+    return {
+        type: 'MediaQuery',
+        loc: this.getLocationFromList(children),
+        children
+    };
+}
+
+export function generate(node) {
+    this.children(node);
+}
+