feat(cli): give the /btw panel a dedicated input editor

[liukx0205]

Related Issue

Stacks on #3619 (which stacks on #3613). This PR is the follow-up that gives the /btw panel its own input box; base is set to feat/btw-image-support because the media path added there (prepareBtwPrompt / trackBtwDispatch, plus the daemon-side ReadMediaFile whitelist) is exactly what the dedicated editor reuses for pasted images.

Problem

The /btw panel had no input of its own: it visually borrowed the main editor (connectedAbove stitching) and intercepted the main send path (sendUserInput) to reroute keystrokes to the side agent. That coupling meant the panel inherited every main-input semantic (queue, steer, bash mode, …) through a fragile interception layer, and pasted images only worked because the shared editor happened to write into the same buffer.

What changed

Design decisions

• Stacking: branched from feat/btw-image-support (feat(cli): send pasted images to the /btw side agent #3619) and based this PR on it. The dedicated editor's image support is a thin reuse of feat(cli): send pasted images to the /btw side agent #3619's prepareBtwPrompt (placeholder → imageStore → daemon file-ref parts at submit); going self-contained would mean duplicating that media chain.
• Layout: kept the existing visual structure with the smallest UX delta. The panel stays where it is; the new editor mounts inside btwPanelContainer directly under the panel with connectedAbove = true, so the panel stitches onto its own editor exactly the way it used to stitch onto the main one. The main editor simply reverts to its plain rounded top border — input and visuals are now fully decoupled.
• Capability trim: the panel's editor is the same CustomEditor class as the main input, but wired with only what a side panel needs:
  • Kept: plain text submit, clipboard image/video paste (same imageStore placeholder → ingestion → prepareBtwPrompt expansion path as the main editor), inline-skill token extraction on submit (existing follow-up behavior), Esc close, ↑↓ panel scroll, Ctrl+C cancel/close.
  • Dropped: no QueuePane/queueing, no Ctrl+S steer, no bash mode (new disableBashMode option on CustomEditor — a leading ! stays literal text), no slash-command/@-mention autocomplete provider, no Ctrl+B/T/P/N bindings, no input history. Placeholder hint stays in the panel body ("Ready for a side question…") and the border hint ("Esc close · ↑↓ scroll") rather than inventing an editor placeholder concept.
• Focus: opening the panel focuses its editor; Esc/close (including clear() on session reset) returns focus to the main editor.

By file

• components/editor/custom-editor.ts — new disableBashMode option guarding both !-mode entry paths (typed and pasted).
• controllers/btw-panel.ts — open() now constructs and wires a dedicated CustomEditor; sendUserInput interception is deleted, replaced by the editor's own onSubmit (busy → restore draft + transient notice; idle → panel.submit with inline-skill extraction); mount/close/clear manage the editor and focus.
• controllers/editor-keyboard.ts — handleClipboardImagePaste became public pasteClipboardImage(target) so both editors share one paste/ingestion path and one imageStore.
• kimi-tui.ts — removed the two btwPanelController.sendUserInput interception calls from sendNormalUserInput / sendInlineSkillUserInput; added pasteImageIntoEditor (BtwPanelHost) delegating to the shared paste path.

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue (external PRs: the issue must have a maintainer's /approve).
• I have added tests that prove my feature works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

[changeset-bot]

🦋 Changeset detected

Latest commit: 9818178

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@moonshot-ai/kimi-code	Minor

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[pkg-pr-new]

pnpm dlx https://pkg.pr.new/@moonshot-ai/kimi-code@9818178

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commit: 9818178

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Restore focus to the /btw editor after modal dialogs

When /btw is opened while the main agent is still running and that agent raises an approval or question dialog, closing the dialog calls KimiTUI.restoreEditor(), which always focuses state.editor (kimi-tui.ts:3764-3768) instead of this dedicated editor. The panel remains visible, but subsequent typing and Enter now go through the main send path because this commit also removed the old /btw interception, so the user's intended follow-up can be queued or sent to the wrong agent. Modal restoration needs to return focus to the active panel editor when one exists.

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[liukx0205]

Closing: product focus moved to the desktop /btw panel (kimi-code-app). The TUI-side dedicated input may be revisited later.

[liukx0205]

Closing: product focus moved to the desktop /btw panel (kimi-code-app). The TUI-side dedicated input may be revisited later.