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/cmaps/CNS2-V.bcmap

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+àRCopyright 1990-2009 Adobe Systems Incorporated.
+All rights reserved.
+See ./LICENSEáCNS2-H

public/pdfjs-viewer/cmaps/ETenms-B5-H.bcmap

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+àRCopyright 1990-2009 Adobe Systems Incorporated.
+All rights reserved.
+See ./LICENSEá	ETen-B5-H`
 ^

public/pdfjs-viewer/cmaps/GB-H.bcmap

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+àRCopyright 1990-2009 Adobe Systems Incorporated.
+All rights reserved.
+See ./LICENSE

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