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/vitest/suppress-warnings.cjs

@@ -0,0 +1,23 @@
+// borrowed from tsx implementation:
+// https://github.com/esbuild-kit/tsx
+
+const ignoreWarnings = new Set([
+  '--experimental-loader is an experimental feature. This feature could change at any time',
+  'Custom ESM Loaders is an experimental feature. This feature could change at any time',
+  'Custom ESM Loaders is an experimental feature and might change at any time',
+  'VM Modules is an experimental feature and might change at any time',
+  'VM Modules is an experimental feature. This feature could change at any time',
+])
+
+const { emit } = process
+
+process.emit = function (event, warning) {
+  if (
+    event === 'warning'
+    && ignoreWarnings.has(warning.message)
+  )
+    return
+
+  // eslint-disable-next-line prefer-rest-params
+  return Reflect.apply(emit, this, arguments)
+}