fix(terminal): don't hijack Space during IME composition (Korean input)

[HAN-oQo]

Problem

Korean (and any IME-composed) input is corrupted in terminals: pressing space between words drops or reorders the in-progress Hangul syllable — e.g. typing 녕 produces 녕 or loses the syllable entirely. This makes CLI sessions nearly unusable for Korean/Japanese/Chinese typists.

Root cause

The push-to-talk Space handler added in #22 (public/terminal-manager.js) intercepts every plain-Space keydown, calls e.preventDefault(), writes a raw ' ' straight to the PTY, and returns false.

The problem is ordering. In xterm's _keyDown, the custom key handler runs before the IME composition helper:

if (this._customKeyEventHandler && false === this._customKeyEventHandler(e)) return false; // ← runs FIRST
if (!t && !this._compositionHelper.keydown(e)) return ..., false;                          // ← IME check runs AFTER

During Korean composition, the Space keydown fires with isComposing === true / keyCode === 229. The handler preventDefaults it (blocking the composition commit), sends a raw space out of order, and returns false so _compositionHelper.keydown() never runs. Since Korean is space-separated, this breaks essentially every word.

Fix

Gate the direct-send path on !isImeComposing(e) so it only fires when no IME is composing — which is exactly when push-to-talk needs it. During composition the event now falls through to xterm's composition helper for correct commit behavior.

function isImeComposing(e) { return e.isComposing === true || e.keyCode === 229; }

function shouldSendSpaceDirectly(e) {
  return e.key === ' '
    && !e.ctrlKey && !e.altKey && !e.metaKey && !e.shiftKey
    && !isImeComposing(e);
}

Push-to-talk (Hold Space to record) is unaffected: with no IME composing, isComposing is false and keyCode is 32, so the direct-send path still fires on every key-repeat.

Testing

• Extracted the decision into a pure, exported predicate and added test/terminal-input.test.js (5 cases: plain space → direct send; composing via isComposing; composing via keyCode 229; modifier combos; non-space keys).
• npm test → all green.
• Not yet verified with live IME typing in the running app — reviewers with a Korean/Japanese/Chinese input source can confirm end-to-end.

🤖 Generated with Claude Code