Implement new functionality to allow embedding attachments into PDF documents. The feature includes:
- UI for selecting PDF and files to attach
- Logic to embed files while preserving metadata
- Display of attached files with size information
- Download of modified PDF with embedded files
Add new linearize PDF tool that optimizes PDFs for fast web viewing using qpdf-wasm. Includes UI components, logic implementation, and test updates. The tool processes multiple PDFs and downloads them in a ZIP archive.