fix(ssh): give up the wrapper's escape key on screen hosts - #175
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The tmux branch releases its prefix so a user's own tmux keeps C-b (#159), but the screen fallback kept screen's default C-a. The outer wrapper therefore swallowed it: a bare `C-a d` inside a nested screen detached *our* session, the SSH channel closed, and the app silently reconnected — the user's own screen never saw the key. screen has no `prefix None` equivalent; `escape` always names some key. It is now pointed at \377, a byte no key produces in a UTF-8 terminal, which is as close to "no escape key" as screen gets. The one theoretical cost is a latin-1 session where 0xFF is ÿ. Verified on a screen-only host (GNU screen 5.0.2) through the app: attached to the user's own session from inside a Voltius session, `C-a d` now prints `[detached from 9616.mine]` and leaves the wrapper attached, where before the wrapper flipped to (Detached) and reconnected underneath.
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Follow-up to #170 / #159, found while verifying the GNU screen half of that fix end to end.
The gap
#170 made the tmux wrapper transparent —
unset TMUX, andprefix NonesoC-bbelongs to whatever the user runs inside. The screen fallback got the environment half but not the key half: our screen rc sets noescape, so the wrapper kept screen's defaultC-aand intercepted it.Observed on a screen-only host, driving the app and polling the host while sending
C-a dfrom inside a nestedscreen -r:The SSH channel then closed and the app reconnected under the user — their own screen never saw
C-a.The fix
screen has no
prefix Noneequivalent:escapealways names some key. It is pointed at\377instead — a byte no key produces in a UTF-8 terminal — which is as close to "no escape key" as screen offers. The only theoretical cost is a latin-1 session where 0xFF isÿ.No version gate:
escapeand octal escapes long predate any screen still in use, and a screen that rejected the line would simply keep its default key.screen -x(the attach path) joins the running server, which keeps the setting this rc gave it at create time — same reasoning as the existingtruecolorline.Verification
Same host (GNU screen 5.0.2), same gesture, through the app:
The pane prints
[detached from 9616.mine]and returns to the wrapper's shell, with the session timer running continuously — no reconnect.cargo test --lib shell_integration: 22/22,cargo fmt --checkclean.