v1.91

Performance Improvement

• ~11% speedup on 64-bit systems by reducing unnecessary masking operations
• Reduced masks from 128 to 68 per 64-byte block

Other Changes

• Added GitHub Actions workflows for testing (Perl 5.16-5.38 + 32-bit)
• Added perltidy formatting check in CI
• Added CLAUDE.md with architecture documentation
• Applied perltidy formatting for consistent code style