fix(web): separate expanded tool output from adjacent hover highlights

[dominic-r]

Hovering a command directly below an expanded tool result made the two backgrounds look joined. Add a 4px bottom margin to expanded rows so the next hover highlight stays separate while collapsed rows keep their existing height.

Verified in a real Chromium client with default dark, Ocean, Grove, Ember, Iris, and T3 Chat. The gap increased from 0.375px to 4.375px; collapsed rows remain 24px, keyboard reopening works, and hover clears on pointer exit. Web and desktop share this component.

Validation: 154 focused timeline tests passed, web typecheck passed, and targeted formatting and lint passed with existing lint warnings.

Before, with the lower command hovered in all six themes:

After, with the same command hovered in all six themes:

Model: GPT-6 Astra. Harness: Codex in T3 Code.

[macroscopeapp]

Approvability

Verdict: Approved at 36fcb9c

Macroscope's review found this PR approvable — This PR adds a single conditional spacing utility to expanded tool rows, separating their output from adjacent hover highlights. It is a localized presentation fix with no changes to data flow, APIs, defaults, or production infrastructure.

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

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Advanced

Run ID: 76e4784d-45f8-4428-84eb-c94a7776935e

📥 Commits

Reviewing files that changed from the base of the PR and between 9086a1f and 36fcb9c.

📒 Files selected for processing (1)

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

Included review availability: Your plan provides up to 10 included reviews per hour; 9 remain after this review.

---

📝 Walkthrough

Walkthrough

The chat timeline adds bottom margin to expanded tool entry rows.

Changes

Chat layout

Layer / File(s)	Summary
Expanded row spacing apps/web/src/components/chat/MessagesTimeline.tsx	PlainWorkEntryRow applies mb-1 when the row is expanded.

Priority: ⬇️ Low

Estimated code review effort: 1 (Trivial) | ~5 minutes

Change: Bug fix

Suggested reviewers: maria-rcks

Merge Risk: ⚪ Minimal · up to 36fcb

This visual-only change is ready to merge with no actionable current risk.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 1…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly and concisely describes the main change: separating expanded tool output from adjacent hover highlights.
Description check	✅ Passed	The description explains what changed and why, includes before-and-after UI screenshots, and documents validation results. The checklist section is omitted, but the description is otherwise substantia…

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

_{Comment @coderabbitai help to get the list of available commands.}