78aca1bb45
Cross-referenced the console-input path against Linux/CachyOS
(local/reference/linux-7.1/drivers/{input,tty}/). Linux applies the
keymap once (vt/keyboard.c) and runs one line discipline (n_tty.c)
shared by the console tty and ptys; RedBear duplicates the keymap
(inputd + fbcond) and CR/LF (fbcond + ptyd) and runs two disciplines
bridged by getty — which is where typed characters are lost (echoed but
not executed). Plan: inputd owns the keymap and emits the full byte
stream (incl. escape sequences); fbcond becomes display-only passthrough
(no keymap, no CR/LF, no cooking); ptyd is the sole line discipline.
Staged, each stage independently bootable; validation needs the build
green (acpi-rs currently blocks it).