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/entities/dist/commonjs/decode-codepoint.d.ts

@@ -0,0 +1,19 @@
+/**
+ * Polyfill for `String.fromCodePoint`. It is used to create a string from a Unicode code point.
+ */
+export declare const fromCodePoint: (...codePoints: number[]) => string;
+/**
+ * Replace the given code point with a replacement character if it is a
+ * surrogate or is outside the valid range. Otherwise return the code
+ * point unchanged.
+ */
+export declare function replaceCodePoint(codePoint: number): number;
+/**
+ * Replace the code point if relevant, then convert it to a string.
+ *
+ * @deprecated Use `fromCodePoint(replaceCodePoint(codePoint))` instead.
+ * @param codePoint The code point to decode.
+ * @returns The decoded code point.
+ */
+export declare function decodeCodePoint(codePoint: number): string;
+//# sourceMappingURL=decode-codepoint.d.ts.map