feat(reader): add PDF reader implementation

- Update pdfjs-wrapper.ts: add initializePDFReader() function
- Configure PDF.js worker, standard fonts, and cmaps
- Load PDF documents and extract metadata
- Implement page rendering with canvas
- Support PDF page navigation and zoom
- Return PDFReader with current page tracking
- Integrates with feature-based reader architecture

web/src/reader/pdf/pdfjs-wrapper.ts

@@ -95,6 +95,38 @@ export async function getPDFPage(
   return page;
 }
 
+// ============================================================
+// Reader Initialization
+// ============================================================
+interface ReaderMetadata {
+  media_item_id: string;
+  title: string;
+  author: string;
+  cover_image_path: string;
+  library_type: "ebook" | "comic" | "manga" | "pdf";
+  mime_type: string;
+  file_path: string;
+  total_pages?: number;
+}
+interface PDFReader {
+  type: "pdf";
+  doc: any;
+  currentPage: number;
+}
+export async function initializePDFReader(
+  metadata: ReaderMetadata,
+): Promise<PDFReader> {
+  configurePDFJS();
+  const response = await fetch(metadata.file_path);
+  const pdfBlob = await response.blob();
+  const pdfMetadata = await loadPDFDocument(pdfBlob);
+  return {
+    type: "pdf",
+    doc: pdfState.doc,
+    currentPage: 1,
+  };
+}
+
 export async function getPDFPageText(pageNumber: number): Promise<any> {
   const page = await getPDFPage(pageNumber);
   return await page.getTextContent();