fix(reader): correct PDF import path after directory restructuring

Update import statement for getPDFPage to use the new directory structure
where PDF-related utilities are now located under formats/pdf/ instead of
the direct pdf/ directory.

This resolves a runtime import error that would occur when attempting to
render PDF pages in the reader interface.

web/src/reader/core/reader-navigation.ts

@@ -366,7 +366,7 @@ async function renderPDFPage() {
   const container = document.getElementById("reader-content");
   if (!container) return;
 
-  const { getPDFPage } = await import("../pdf/pdfjs-wrapper");
+  const { getPDFPage } = await import("../formats/pdf/pdfjs-wrapper");
 
   try {
     const page = await getPDFPage(state.currentReader.currentPage);