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/assertion-error/package.json

@@ -0,0 +1,29 @@
+{
+    "name": "assertion-error",
+    "version": "1.1.0",
+    "description": "Error constructor for test and validation frameworks that implements standardized AssertionError specification.",
+    "author": "Jake Luer <jake@qualiancy.com> (http://qualiancy.com)",
+    "license": "MIT",
+    "types": "./index.d.ts",
+    "keywords": [
+        "test",
+        "assertion",
+        "assertion-error"
+    ],
+    "repository": {
+        "type": "git",
+        "url": "git@github.com:chaijs/assertion-error.git"
+    },
+    "engines": {
+        "node": "*"
+    },
+    "main": "./index",
+    "scripts": {
+        "test": "make test"
+    },
+    "dependencies": {},
+    "devDependencies": {
+        "component": "*",
+        "typescript": "^2.6.1"
+    }
+}