The PR migrated the app.js tab-nav handler to physical e.code but left xterm's
pass-through gate (terminal-ui.js) matching ev.key digits. Consequences:
- Alt+[ / Alt+] (the new bindings) were never in the gate, so xterm sent ESC[ / ESC]
to the PTY on every platform AS WELL AS switching the session.
- Alt+digit on a remapped macOS Option layout (Option+1 -> "¡") didn't match the
ev.key '0'-'9' gate either, so xterm injected ESC<char> — on exactly the layouts
this PR exists to fix.
Update the xterm gate to mirror app.js exactly: suppress when
`ev.altKey && !ctrl && !shift && /^(Digit[1-9]|BracketLeft|BracketRight)$/.test(ev.code)`.
Returning false there tells xterm not to write to the PTY, so the shortcut switches
the tab with no stray escape sequence.
Also: relabel the docs Alt/Option (the mechanism is layout/OS-independent, so the
shortcut works for Linux/Windows Alt users too — "Option" alone was Mac-only wording),
and add a keyboard-shortcuts test asserting terminal-ui.js gates on the same physical
codes so this desync can't regress (a grep the original test missed).
Verified: keyboard-shortcuts test 4/4, check:frontend-syntax, check:public-assets,
format:check all clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Tab-switch shortcuts matched e.key, so on macOS Option+1 emits a special
character ('¡', not '1') and the shortcut silently failed. Switch to physical
e.code (Digit1-9), which is layout-independent. Also adds Option+[ / Option+]
for previous / next session. Help modal + README updated.
Test: test/keyboard-shortcuts.test.ts.