feat(pdfjs-viewer): add initial PDF.js viewer assets and configuration

Add initial set of PDF.js viewer files including:
- WASM binaries for PDF rendering
- Standard fonts and CMAP files for text rendering
- UI icons and SVG assets for toolbar buttons
- TypeScript declaration files
- Loading animation GIF
- Annotation icons and UI elements

This provides the base functionality for the PDF viewer including:
- Document rendering
- Navigation controls
- Zoom functionality
- Page display options
- Annotation tools
- Document properties

public/pdfjs-viewer/images/secondaryToolbarButton-selectTool.svg

@@ -0,0 +1,3 @@
+<svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
+<path d="M0.371588 2.93131C-0.203366 1.33422 1.3342 -0.20335 2.93129 0.371603L2.93263 0.372085L12.0716 3.68171C12.0718 3.68178 12.0714 3.68163 12.0716 3.68171C13.4459 4.17758 13.8478 5.9374 12.8076 6.9776L11.8079 7.97727L14.6876 10.8569C15.4705 11.6398 15.4705 12.9047 14.6876 13.6876L13.6476 14.7276C12.8647 15.5105 11.5998 15.5105 10.8169 14.7276L7.93725 11.8479L6.97758 12.8076C5.93739 13.8478 4.17779 13.4465 3.68192 12.0722C3.68184 12.072 3.682 12.0724 3.68192 12.0722L0.371588 2.93131ZM1.78292 2.42323C1.78298 2.4234 1.78286 2.42305 1.78292 2.42323L5.09281 11.5629C5.21725 11.9082 5.65728 12.0066 5.91692 11.7469L7.93725 9.72661L11.8776 13.6669C12.0747 13.864 12.3898 13.864 12.5869 13.6669L13.6269 12.6269C13.824 12.4298 13.824 12.1147 13.6269 11.9176L9.68659 7.97727L11.7469 5.91694C12.0066 5.65729 11.9081 5.21727 11.5629 5.09283L11.5619 5.09245L2.42321 1.78293C2.42304 1.78287 2.42339 1.783 2.42321 1.78293C2.02067 1.63847 1.63846 2.02069 1.78292 2.42323Z" fill="black"/>
+</svg>