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/parse5/dist/tokenizer/preprocessor.d.ts

@@ -0,0 +1,36 @@
+import { ERR, type ParserError, type ParserErrorHandler } from '../common/error-codes.js';
+export declare class Preprocessor {
+    private handler;
+    html: string;
+    pos: number;
+    private lastGapPos;
+    private gapStack;
+    private skipNextNewLine;
+    lastChunkWritten: boolean;
+    endOfChunkHit: boolean;
+    bufferWaterline: number;
+    private isEol;
+    private lineStartPos;
+    droppedBufferSize: number;
+    line: number;
+    constructor(handler: {
+        onParseError?: ParserErrorHandler | null;
+    });
+    /** The column on the current line. If we just saw a gap (eg. a surrogate pair), return the index before. */
+    get col(): number;
+    get offset(): number;
+    getError(code: ERR, cpOffset: number): ParserError;
+    private lastErrOffset;
+    private _err;
+    private _addGap;
+    private _processSurrogate;
+    willDropParsedChunk(): boolean;
+    dropParsedChunk(): void;
+    write(chunk: string, isLastChunk: boolean): void;
+    insertHtmlAtCurrentPos(chunk: string): void;
+    startsWith(pattern: string, caseSensitive: boolean): boolean;
+    peek(offset: number): number;
+    advance(): number;
+    private _checkForProblematicCharacters;
+    retreat(count: number): void;
+}