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-format/locale/it-IT.json

@@ -0,0 +1,10 @@
+{
+  "dateTime": "%A %e %B %Y, %X",
+  "date": "%d/%m/%Y",
+  "time": "%H:%M:%S",
+  "periods": ["AM", "PM"],
+  "days": ["Domenica", "Lunedì", "Martedì", "Mercoledì", "Giovedì", "Venerdì", "Sabato"],
+  "shortDays": ["Dom", "Lun", "Mar", "Mer", "Gio", "Ven", "Sab"],
+  "months": ["Gennaio", "Febbraio", "Marzo", "Aprile", "Maggio", "Giugno", "Luglio", "Agosto", "Settembre", "Ottobre", "Novembre", "Dicembre"],
+  "shortMonths": ["Gen", "Feb", "Mar", "Apr", "Mag", "Giu", "Lug", "Ago", "Set", "Ott", "Nov", "Dic"]
+}