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/gopd/.eslintrc

@@ -0,0 +1,16 @@
+{
+	"root": true,
+
+	"extends": "@ljharb",
+
+	"rules": {
+		"func-style": [2, "declaration"],
+		"id-length": 0,
+		"multiline-comment-style": 0,
+		"new-cap": [2, {
+			"capIsNewExceptions": [
+				"GetIntrinsic",
+			],
+		}],
+	},
+}