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/dom-accessibility-api/dist/is-inaccessible.d.ts

@@ -0,0 +1,31 @@
+export interface IsInaccessibleOptions {
+    getComputedStyle?: typeof window.getComputedStyle;
+    /**
+     * Can be used to return cached results from previous isSubtreeInaccessible calls.
+     */
+    isSubtreeInaccessible?: (element: Element) => boolean;
+}
+/**
+ * Partial implementation https://www.w3.org/TR/wai-aria-1.2/#tree_exclusion
+ * which should only be used for elements with a non-presentational role i.e.
+ * `role="none"` and `role="presentation"` will not be excluded.
+ *
+ * Implements aria-hidden semantics (i.e. parent overrides child)
+ * Ignores "Child Presentational: True" characteristics
+ *
+ * @param element
+ * @param options
+ * @returns {boolean} true if excluded, otherwise false
+ */
+export declare function isInaccessible(element: Element, options?: IsInaccessibleOptions): boolean;
+export interface IsSubtreeInaccessibleOptions {
+    getComputedStyle?: typeof window.getComputedStyle;
+}
+/**
+ *
+ * @param element
+ * @param options
+ * @returns {boolean} - `true` if every child of the element is inaccessible
+ */
+export declare function isSubtreeInaccessible(element: Element, options?: IsSubtreeInaccessibleOptions): boolean;
+//# sourceMappingURL=is-inaccessible.d.ts.map