- class2/commands.rs: EIA/TIA-592 Class 2 AT command definitions
- class2/send.rs: Class2Send implementation for simpler fax sending
- CLI: Add --class option for send command (1 or 2)
- CLI: Add --class2 flag for test command
- Tested with Conexant V90 modem - all Class 2 commands working
- pdf.rs: Ghostscript-based PDF to TIFF-F conversion
- tiff_to_fax_document: Parse TIFF and convert to 1-bit fax format
- CLI: Add 'convert' subcommand for dry testing
- CLI: Add resolution option for send command
- Test files for PDF/TIFF conversion validation