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/autoprefixer/lib/hacks/flex-wrap.js

@@ -0,0 +1,19 @@
+let Declaration = require('../declaration')
+let flexSpec = require('./flex-spec')
+
+class FlexWrap extends Declaration {
+  /**
+   * Don't add prefix for 2009 spec
+   */
+  set(decl, prefix) {
+    let spec = flexSpec(prefix)[0]
+    if (spec !== 2009) {
+      return super.set(decl, prefix)
+    }
+    return undefined
+  }
+}
+
+FlexWrap.names = ['flex-wrap']
+
+module.exports = FlexWrap