fix(web): composer keeps its border while resting and expanding

[flamboh]

Note

🤖 Claude Opus 5.5 on behalf of Oliver

Problem

When the composer switches between resting (compact) and expanded while the model strip is showing, its 1px outline disappears for the whole animation. During that transition ComposerSurface.Main paints the glass background so the strip can slide under the input. Main sits above ComposerSurface.Host, so that background covers the Host outline, and Main's own outline is hidden unless a banner is attached.

Fix

Main now shows its own outline while data-model-strip-transition is set on the shell, the same way it already does when a banner is attached. This adds one class in ComposerSurface.tsx.

Evidence

Captured mid-expand with the composer animation slowed down (the shell still has data-model-strip-transition set), at 2× DPR.

Before (light)

After (light)

Before (dark)

After (dark)

Rest → expand, slowed 8×. Before:

https://gh-file-drop-api-prod-galwoqjslzlnws6s.oliver-boorstein.workers.dev/f/ea51f1e96cfda6b2/composer-border-before.mp4

After:

https://gh-file-drop-api-prod-galwoqjslzlnws6s.oliver-boorstein.workers.dev/f/d1d2ad8129e66e09/composer-border-after.mp4

Validation

• Headless Chromium against a worktree dev server: mid-transition, getComputedStyle(main, '::after').display is none before the fix and block after.
• Checked by hand in a browser on the dev server.
• vp lint on the changed file.

Made by Claude Opus 5.5 in Claude Code (T3 Code).

[macroscopeapp]

Approvability

Verdict: Approved at 386ba7b

Macroscope's review found this PR approvable — This is a focused one-line UI fix that restores the composer’s existing outline only during an already-scoped expand/collapse animation. It introduces no new workflow, data/API change, deployment change, or static-analysis override.

^{You can add or adjust custom eligibility rules. Learn more.}

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between bed9239 and 386ba7b.

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📒 Files selected for processing (1)

• apps/web/src/components/chat/ComposerSurface.tsx

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📝 Walkthrough

Walkthrough

ComposerSurface.Main now displays its outline during model-strip transitions, in addition to when an attached composer banner is present.

Changes

Composer outline behavior

Layer / File(s)	Summary
Update outline condition apps/web/src/components/chat/ComposerSurface.tsx	Main now enables its outline during model-strip transitions as well as when an attached composer banner is present.

Priority: ⬇️ Low

Estimated code review effort: 1 (Trivial) | ~3 minutes

Change: Bug fix

Suggested reviewers: juliusmarminge

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Merge Risk: ⚪ Minimal · up to 386ba

The outline is enabled for the model-strip transition and its marker is cleaned up afterward. No actionable merge-blocking risk is evident.

Pre-merge checks | 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check		The title clearly identifies the composer border issue during resting and expanding transitions.
Description check		The description clearly documents the problem, fix, visual evidence, validation steps, and tool attribution. It does not include a dedicated Scope and approval section or explicitly explain why prior …
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

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