The previous commit defined parseCSIuBytes but failed to insert the
handler into Update(). Now properly inserted before the textinput
fallback. Add 10 test cases for parseCSIuBytes covering ctrl+alt+f/c/
m/p/h, ctrl+shift+c, alt+c, and invalid sequences.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
JiXieShi