- Added debug menu options for terminal state and protocol checks with new handlers.
- Added terminal diagnostics models and collectors to report geometry, protocol flags, and multiplexer data.
- Added protocol-probe utilities to encode RGB PNGs, generate sample content, and render test panels.
- Added support components for verbatim line rendering and OSC66-scaled text rows.
- Added tests validating image encoding, OSC66 output, and terminal state formatting.