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/d3-time/src/hour.js

@@ -0,0 +1,26 @@
+import {timeInterval} from "./interval.js";
+import {durationHour, durationMinute, durationSecond} from "./duration.js";
+
+export const timeHour = timeInterval((date) => {
+  date.setTime(date - date.getMilliseconds() - date.getSeconds() * durationSecond - date.getMinutes() * durationMinute);
+}, (date, step) => {
+  date.setTime(+date + step * durationHour);
+}, (start, end) => {
+  return (end - start) / durationHour;
+}, (date) => {
+  return date.getHours();
+});
+
+export const timeHours = timeHour.range;
+
+export const utcHour = timeInterval((date) => {
+  date.setUTCMinutes(0, 0, 0);
+}, (date, step) => {
+  date.setTime(+date + step * durationHour);
+}, (start, end) => {
+  return (end - start) / durationHour;
+}, (date) => {
+  return date.getUTCHours();
+});
+
+export const utcHours = utcHour.range;