feat(tui): show assistant turn completion time

[EZotoff]

Issue for this PR

Closes #35348

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

Appends the wall-clock completion time after the duration in the TUI turn-summary line. The format follows the user's locale settings via the existing Locale.time() helper.

Before: ▣ Build · gpt-5 · 2.8s
After: ▣ Build · gpt-5 · 2.8s · 3:41 PM

Threads an optional time: string through the turn-summary pipeline:

• runtime.queue.ts computes time: Locale.time(end) at the same Date.now() capture used for duration, and emits it on the turn.duration FooterEvent.
• types.ts adds time?: string to TurnSummary and time: string to the turn.duration event variant.
• footer.ts forwards next.time into writeTurnSummary.
• scrollback.surface.ts and turn-summary.ts accept and append · \${time} to the summary text when present.
• scrollback.writer.tsx renders the optional suffix via the same ternary.
• messageTurnSummaryCommit in turn-summary.ts passes time: Locale.time(completed) so session-replayed history also shows the timestamp.
• packages/tui/src/routes/session/index.tsx AssistantMessage adds a completedTime memo and renders it inside the existing <Show when={duration()}> block — this is the path users see for completed turns.

This is a faithful revival of #32771, which was auto-closed by the needs:compliance bot within 2 hours of being opened for not matching the template. The original implementation and tests are preserved; attribution retained.

How did you verify your code works?

• New test/cli/run/turn-summary.test.ts — unit test on turnSummaryCommit with and without time.
• New case in scrollback.surface.test.ts — exercises writeTurnSummary with time and asserts the rendered row.
• Updated 3 turn-summary assertions in session-replay.test.ts to expect · \${Locale.time(3000)} suffix.
• Updated inline-tool-wrap-snapshot.test.tsx fixture + snapshot to include the time suffix.

33 opencode package tests pass; 17 TUI snapshot tests pass.

Screenshots / recordings

Text-only TUI change. Before/after captured above in What does this PR do?

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

Co-authored-by: joeyparis joeyparis@users.noreply.github.com
Co-authored-by: Sisyphus clio-agent@sisyphuslabs.ai

[EZotoff]

Heads up for reviewers — this is complementary to `/timestamps`, not a duplicate.

OpenCode v1.17.13+ shipped the `session.toggle.timestamps` keybind (packages/tui/src/config/keybind.ts:100) which toggles per-message timestamps next to each individual message in the scrollback (packages/tui/src/routes/session/index.tsx:1426).

This PR adds the timestamp to a different surface: the turn-summary line itself (▣ agent · model · duration), which is rendered by AssistantMessage and is not affected by the `/timestamps` toggle. Verified against plain origin/dev — the turn-summary line still has no time:

▣ Build · gpt-5 · 2.8s          ← current dev
▣ Build · gpt-5 · 2.8s · 3:41 PM ← this PR

If maintainers prefer, this could alternatively be gated behind the same `timestamps` kv signal so the two surfaces stay consistent — happy to revise in that direction.