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/lodash/divide.js

@@ -0,0 +1,22 @@
+var createMathOperation = require('./_createMathOperation');
+
+/**
+ * Divide two numbers.
+ *
+ * @static
+ * @memberOf _
+ * @since 4.7.0
+ * @category Math
+ * @param {number} dividend The first number in a division.
+ * @param {number} divisor The second number in a division.
+ * @returns {number} Returns the quotient.
+ * @example
+ *
+ * _.divide(6, 4);
+ * // => 1.5
+ */
+var divide = createMathOperation(function(dividend, divisor) {
+  return dividend / divisor;
+}, 1);
+
+module.exports = divide;