fix(web): show message copy buttons on touch devices

[maria-rcks]

On mobile web the copy button on user and assistant messages was invisible: both action rows are opacity-0 and only reveal on hover/focus-within, neither of which a touch browser produces, so there was no discoverable way to copy an agent response.

Both rows now stay at opacity-100 under @media (pointer: coarse) using the pointer-coarse: Tailwind variant already used in ChatComposer.tsx and KeybindingsSettings.tsx. Hover/pointer-fine behavior is untouched, so desktop still reveals the row on hover. The timestamp and the revert button share those rows and become visible on touch too, which is the same discoverability win.

Verified: vp run --filter @t3tools/web typecheck passed with no errors; vp lint apps/web/src/components/chat/MessagesTimeline.tsx passed (only pre-existing warnings on unrelated lines); vitest run src/components/chat/MessagesTimeline.test.tsx src/components/chat/MessagesTimeline.logic.test.ts passed 147/147; compiled pointer-coarse:opacity-100 through the repo's Tailwind 4.3.3 and confirmed it emits @media (pointer: coarse) { .pointer-coarse\:opacity-100 { opacity: 100% } }. No test added: the change is class-only and AGENTS.md rules out tests that assert rendered attributes.

Out of scope: apps/mobile is React Native and has its own copy affordance, and the timeline minimap / turn-nav arrows in the same file are already gated to pointer: fine on purpose.

Fixes #2804

UI evidence: unverified. The browser preview host was unavailable in this session, so the changed interaction was not exercised in a real client. Scoped tests, typecheck, and lint pass; a reviewer should exercise the interaction locally before merge.

Done by Claude Opus 5 (1M context) in Claude Code.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Message timestamps and copy controls now remain visible on touch devices instead of requiring hover or focus.

[macroscopeapp]

Approvability

Verdict: Approved at f4f791e

Macroscope's review found this PR approvable — This is a narrowly scoped web UI fix that exposes existing message copy controls on coarse-pointer devices. It changes only responsive visibility styling in one component and has no broader runtime, API, configuration, or deployment impact.

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📥 Commits

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

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📝 Walkthrough

Walkthrough

The message metadata rows for user and assistant messages now use full opacity on coarse-pointer devices. This keeps timestamps and copy controls visible on touch devices.

Changes

Mobile message metadata

Layer / File(s)	Summary
Coarse-pointer metadata visibility apps/web/src/components/chat/MessagesTimeline.tsx	User and assistant metadata rows now apply opacity-100 on coarse-pointer devices, in addition to focus and hover visibility rules.

Estimated code review effort: 1 (Trivial) | ~2 minutes

Severity of issue fixed: Medium

Merge Risk: ⚪ Minimal · up to f4f79

Message copy controls, timestamps, and related actions are now visible on touch devices while desktop interaction behavior remains unchanged. No current merge-blocking risk is identified.

Suggested reviewers: juliusmarminge, t3dotgg

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 2 functions across 1 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly describes the main change: showing message copy buttons on touch devices.
Description check	✅ Passed	The description explains the problem, implementation, behavior on desktop and touch devices, validation performed, and scope. UI evidence and the template checklist are not included, but the descripti…
Linked Issues check	✅ Passed	The class updates make assistant and user message action rows visible on coarse-pointer devices, which provides the discoverable mobile copy action required by issue [#2804]. Desktop hover and focus b…
Out of Scope Changes check	✅ Passed	The change is limited to two relevant class updates in MessagesTimeline.tsx. The additional visibility of timestamps and revert controls is a direct consequence of the shared action rows and remains w…

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