fix(web): let workspace picker fit its content

[chengluyu]

Related Issue

No related issue. This is a focused fix for a reproducible workspace picker layout bug in the web UI.

Problem

The workspace picker measured only the longest shortened path and then used that text width as the width of the entire menu. When all paths were short, the menu became too narrow for workspace names and actions, clipping content and showing a horizontal scrollbar.

What changed

• Remove the hidden measurement probe, pretext calculations, resize listeners, and reactive width state.
• Let CSS Grid and width: max-content size the menu from its complete rendered content.
• Keep the design-system 180px minimum and cap the menu to the conversation pane.
• Ellipsize labels only when the conversation-pane cap is reached.
• Add a patch changeset for @moonshot-ai/kimi-code.

Validation

• pnpm --filter @moonshot-ai/kimi-web typecheck
• pnpm --filter @moonshot-ai/kimi-web test (27 files, 458 tests)
• pnpm --filter @moonshot-ai/kimi-web build
• pnpm --filter @moonshot-ai/kimi-web check:style (passes with the existing warning baseline)
• pnpm exec oxlint apps/kimi-web/src/components/chat/ConversationPane.vue (no errors; one pre-existing warning)
• Real-browser intrinsic sizing checks:
  • Short content uses the 180px minimum with no horizontal overflow.
  • Wider content expands the menu to fit.
  • With a 300px sidebar and 460px preview, a 520px conversation pane caps the menu at 488px with 16px clearance on both sides and no horizontal overflow.
  • Light and dark menu states preserve the same sizing behavior.
• Read-only audit of the original PR diff found no context-specific internal identifiers; this revision only removes measurement code and adds generic CSS.

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue, or explained the problem above.
• I have added tests that prove my feature works. No new component test was added; the existing 458-test web suite and real-browser layout checks cover this focused CSS fix.
• I have run the gen-changesets skill and added a patch changeset.
• I have run the gen-docs check. No documentation update is needed for this focused layout fix.

[changeset-bot]

🦋 Changeset detected

Latest commit: 530e017

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	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[pkg-pr-new]

pnpm dlx https://pkg.pr.new/@moonshot-ai/kimi-code@530e017

npx https://pkg.pr.new/@moonshot-ai/kimi-code@530e017

commit: 530e017

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