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/mdn-data/css/readme.md

@@ -0,0 +1,32 @@
+# MDN CSS data
+
+This folder contains data about the different features of the [CSS](https://developer.mozilla.org/en-US/docs/Web/CSS) language.
+
+## Different types of CSS data
+
+The CSS data is split into these parts:
+
+* **at-rules**:
+[data](https://github.com/mdn/data/blob/master/css/at-rules.json) |
+[schema](https://github.com/mdn/data/blob/master/css/at-rules.schema.json) |
+[docs](https://github.com/mdn/data/blob/master/css/at-rules.md)
+* **properties**:
+[data](https://github.com/mdn/data/blob/master/css/properties.json) |
+[schema](https://github.com/mdn/data/blob/master/css/properties.schema.json) |
+[docs](https://github.com/mdn/data/blob/master/css/properties.md)
+* **selectors**:
+[data](https://github.com/mdn/data/blob/master/css/selectors.json) |
+[schema](https://github.com/mdn/data/blob/master/css/selectors.schema.json) |
+[docs](https://github.com/mdn/data/blob/master/css/selectors.md)
+* **syntaxes**:
+[data](https://github.com/mdn/data/blob/master/css/syntaxes.json) |
+[schema](https://github.com/mdn/data/blob/master/css/syntaxes.schema.json) |
+[docs](https://github.com/mdn/data/blob/master/css/syntaxes.md)
+* **types**:
+[data](https://github.com/mdn/data/blob/master/css/types.json) |
+[schema](https://github.com/mdn/data/blob/master/css/types.schema.json) |
+[docs](https://github.com/mdn/data/blob/master/css/types.md)
+* **units**:
+[data](https://github.com/mdn/data/blob/master/css/units.json) |
+[schema](https://github.com/mdn/data/blob/master/css/units.schema.json) |
+[docs](https://github.com/mdn/data/blob/master/css/units.md)