fix(desktop): prevent Enter from submitting during IME composition

[satotakumi]

What does this PR do?

Prevents the desktop app's Enter-to-submit branches from firing while an IME composition is active. Users typing in Japanese, Chinese, Korean, Vietnamese, or any other compositional input method were seeing their messages sent mid-conversion instead of committing the candidate.

The fix is a single !event.nativeEvent.isComposing guard added to every Enter handler in the desktop renderer that previously had none.

This is the right approach because:

• event.nativeEvent.isComposing is the standard Chromium signal for active IME composition, exposed as a property on every KeyboardEvent regardless of IME implementation.
• Referring to the native event (rather than the React synthetic isComposing) is safer across Electron's bundled Chromium versions.
• The five affected sites share an identical one-line pattern, so bundling them into one PR keeps reviewable context together and avoids four future duplicate issues.

Related Issue

Fixes #37483

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 🔒 Security fix
• 📝 Documentation update
• ✅ Tests (adding or improving test coverage)
• ♻️ Refactor (no behavior change)
• 🎯 New skill (bundled or hub)

Changes Made

Added !event.nativeEvent.isComposing to the following Enter handlers:

• apps/desktop/src/app/chat/composer/index.tsx — main composer submit (L592) and / @ trigger popover (L573)
• apps/desktop/src/components/assistant-ui/thread.tsx — message edit submit (L1239) and trigger popover (L1213)
• apps/desktop/src/components/desktop-onboarding-overlay.tsx — API key input (L486) and auth code input (L554)
• apps/desktop/src/app/chat/sidebar/session-actions-menu.tsx — session rename input (L227)

Each file is a one-line change; total diff is 4 files, 7 insertions, 7 deletions.

How to Test

Reproduction (before fix):

1. Launch Hermes Desktop on macOS.
2. Enable a Japanese IME (macOS "Japanese Input", ATOK, or Google Japanese Input).
3. Type きょうは (pre-conversion kana) in the chat composer.
4. The candidate list appears (e.g. "今日", "京は").
5. Press Enter to commit the candidate.
6. Observe: the commit fires and the message is sent immediately.

Verification (after fix):

1. Repeat the same reproduction steps.
2. Observe: Enter commits the selected candidate. The composer retains the committed text. No message is sent.
3. A subsequent Enter (or a click on the send button) sends the message as expected — Enter-to-send behaviour is preserved once composition has ended.

Additional verification targets:

• The / and @ trigger popovers still close on Enter/Tab and commit on click when composing is not active.
• The message edit composer still submits on Enter after typing a revised message.
• The session rename dialog still submits on Enter after typing a new title.

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits (fix(scope):, feat(scope):, etc.)
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix/feature (no unrelated commits)
• I've run pytest tests/ -q and all tests pass — N/A (no Desktop-specific Python tests exist; Desktop is pure TypeScript/Electron)
• I've added tests for my changes — Not added. jsdom does not model KeyboardEvent.isComposing reliably (it's a native Chromium property set by the IME subsystem), so a jsdom unit test here would not catch the real-world failure. Manual IME verification was preferred; I'm happy to add a jsdom test if maintainers want one.
• I've tested on my platform: macOS 26.5 (darwin-arm64, Apple Silicon) with the built-in Japanese IME

Documentation & Housekeeping

• I've updated relevant documentation (README, docs/, docstrings) — or N/A
• I've updated cli-config.yaml.example if I added/changed config keys — or N/A
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — or N/A
• I've considered cross-platform impact (Windows, macOS) per the compatibility guide — or N/A
• I've updated tool descriptions/schemas if I changed tool behavior — or N/A

For New Skills

N/A (this is a bug fix, not a new skill).

Screenshots / Logs

Not applicable. This is a pure input-handling fix — no visual change. The difference is observable only with an IME active and is verified by the behavioural steps in "How to Test" above.

Additional reviewer notes

• Cross-platform note: isComposing is a standard KeyboardEvent property in Chromium, WebKit, and Firefox — Windows, Linux, and macOS all behave identically here. The fix doesn't introduce any platform-specific code.
• Tab key: the trigger popover branches now also skip Tab during composition. This is a safety measure for symmetry; Tab is not a key users press while composing, but adding the guard keeps the Enter/Tab branches uniform.
• Lower-priority sites: the onboarding overlay (API key / auth code input) and session rename are rarely hit by IME users in practice, but share the same pattern and are patched for completeness to prevent duplicate future issues.

[combatsheep]

Reviewed the IME-composition guards across composer, edit, onboarding, and rename flows. The native check is applied consistently at every Enter/Tab submit path and the scope matches the reported bug. Approving.

[tonydwb]

Code Review Summary

Verdict: Approved

Clean IME composition guard fix. Adds !event.nativeEvent.isComposing checks to Enter/Tab key handlers across 4 files (composer, session-actions, thread, onboarding). Standard pattern used throughout the web ecosystem. +7/-7 lines — minimal, targeted, correct.

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Reviewed by Hermes Agent

[teknium1]

Thanks for the focused IME fix. The primary chat-composer behavior is already covered on current main, but the same bug class remains in refactored sibling paths.

Problems

• The original thread.tsx and desktop-onboarding-overlay.tsx targets no longer exist. Their live replacements still submit without a composition guard: apps/desktop/src/components/assistant-ui/thread/user-edit-composer.tsx:545,573, apps/desktop/src/components/onboarding/index.tsx:647,660, and apps/desktop/src/components/onboarding/flow.tsx:85.
• The composer hunk is now redundant: apps/desktop/src/app/chat/composer/index.tsx:370 already returns for either composingRef.current or event.nativeEvent.isComposing via 40420a619.

Suggested changes

• Port the remaining guards to the current paths, including the newer local-key input at components/onboarding/index.tsx:660.
• Add focused coverage that composing Enter does not invoke each ported submit action.

Automated hermes-sweeper review.

[teknium1]

Thanks for this fix! It was salvaged into #86760 (cherry-picked onto current main with your authorship preserved in the commit history) and is now merged. Closing since the work has landed.