A test pins `ssh <app>@<forge> pulls`: a title cannot carry a terminal escape, and a refused viewer gets the terminal's own refusal

src/apps/tty_pulls.ts writes pull titles to a person's terminal; a title is text anyone with write can set. No test imports it.

Done, in test/tty-pulls.test.ts:

[ ] plainTitle drops ESC sequences, newlines, U+2028/U+2029 and zero-width format characters, and bounds the line at 120 characters.
[ ] servePulls with a fake session writes one #n title · <check word> line per open pull and exits 0.
[ ] A viewer appGate refuses gets forge: <ttyRefusalText> on stderr, nothing on stdout, and exit 1.
[ ] The escape assertion fails if the control-character class is removed.

Files: test/tty-pulls.test.ts only. Suggested: scout.

A test pins `ssh <app>@<forge> pulls`: a title cannot carry a terminal escape, and a refused viewer gets the terminal's own refusal #6825