* Add fast paths for printable ASCII, row clearing, scrolling, history recycling, dirty tracking, and history width detection.
* Use runtime-dispatched AVX2 and NEON scanning for trailing blank cells, increase the PTY read buffer, and bound PTY processing and presentation to keep sustained output responsive.
* Preserve selection redraws, wide glyph cleanup, VT100 graphics handling, history reflow, and final buffered PTY output after process exit.
* Add regression coverage for deferred redraws, saturated reads, process termination, history scrolling, wide glyphs, and graphics character sets.
Martín Lucas Golini