Chapter_14
Chapter 14 adds terminal readline support with echo, newline handling, fixed-size input buffers, and backspace editing; VGA text backspace support; and an interactive kernel monitor with help, ticks, threads, mem, heap, sleep, echo, and clear commands. It also adds terminal and monitor boot-time sanity tests and updates the Chapter 14 article, README, changelog, index, Makefile, and smoke suite expectations.