- Add new tool to apply cryptographic signatures to PDFs using X.509 certificates
- Support PKCS#12 (.pfx, .p12) and PEM certificate formats
- Create PKCS#7 detached signatures compatible with all major PDF viewers
- Optional visible signature with customizable position, image, and text overlay
- Add translations for English, German, Vietnamese, and Chinese
- Simplify Dockerfile by removing redundant BASE_URL handling logic and complex RUN commands
- Change SIMPLE_MODE default from true to false for production builds
- Fix indentation inconsistencies in Dockerfile conditional statements
- Move favicon link tags from body to head section in all HTML files for proper semantic structure
- Replace inline favicon links with img tag in navigation logo across all pages
- Update README.md documentation to clarify BASE_URL trailing slash requirements
- Remove commented-out legacy Dockerfile code for cleaner maintenance
- Consolidate favicon declarations in document head for better performance and SEO
