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-disabled.js

@@ -0,0 +1,20 @@
+"use strict";
+
+exports.__esModule = true;
+exports.isDisabled = isDisabled;
+var _getRole = require("./getRole");
+var elementsSupportingDisabledAttribute = new Set(["button", "fieldset", "input", "optgroup", "option", "select", "textarea"]);
+
+/**
+ * Check if an element is disabled
+ * https://www.w3.org/TR/html-aam-1.0/#html-attribute-state-and-property-mappings
+ * https://www.w3.org/TR/wai-aria-1.1/#aria-disabled
+ *
+ * @param element
+ * @returns {boolean} true if disabled, otherwise false
+ */
+function isDisabled(element) {
+  var localName = (0, _getRole.getLocalName)(element);
+  return elementsSupportingDisabledAttribute.has(localName) && element.hasAttribute("disabled") ? true : element.getAttribute("aria-disabled") === "true";
+}
+//# sourceMappingURL=is-disabled.js.map