feat(tui): choose which transcript entries show timestamps

[Nowaker]

Issue for this PR

Closes #42498

Builds on #53195 (turn_timing, Locale.todayTimeOrDateFirst); this branch contains that commit, so the diff to review is the last commit only.

Type of change

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

What does this PR do?

Only prompts (/timestamps) and assistant turn footers (/turn-times, turn_timing.time) can show when something happened. Tool calls, thinking blocks, text blocks, errors and compactions never do, so in a long run there is no way to see when a step finished or how long a tool call ran.

This adds a timestamps option to tui.json. It names the entry types that show a timestamp: "all", "none", a comma-separated list such as "user,tool", or an array. The types are user, assistant, text, reasoning, tool, error and compaction.

• tool: inline rows append · <end> · <duration>, block tools append it to their title (or add a line when they have no title). Both read state.time of completed and errored calls through formatToolTimestamp.
• reasoning: the time goes before the existing duration (Thought: 8:05 PM · 359ms).
• text, error: a muted time line under the block or inside the error box.
• compaction: the time goes in the divider title.
• user, assistant: the existing prompt time and turn-footer time.

All of them use Locale.todayTimeOrDateFirst from #53195: time of day if today, date then time otherwise.

When timestamps is unset nothing changes, and /timestamps, /turn-times and turn_timing.time work and persist as before. When it is set, the list decides every type each time the TUI starts and overrides turn_timing.time. /timestamps and /turn-times still flip prompt and turn times, but only until the TUI exits. I didn't let kv win here: kv.json usually already contains "timestamps", because the kv store writes its in-memory defaults together with any other key, so a kv-wins rule would make the option do nothing for most existing installs.

opencode doesn't ship a commented tui.jsonc template, so the schema description is the in-editor documentation. It lists every value. tui.mdx gets a Timestamps section with a table of the types.

How did you verify your code works?

• bun typecheck in packages/tui and packages/opencode (pre-push turbo typecheck: 30/30).
• New tests: timestamps decoding (all, none, spaced list, array, and rejection of unknown names, all,user, a trailing comma and ["all"]); formatToolTimestamp for each tool state; an InlineToolRow render with a timestamp; loads timestamps config in packages/opencode/test/config/tui.test.ts. The four plugin-merge failures in that file also fail on dev.
• I ran the TUI on a throwaway tmux socket with isolated XDG_* dirs, against a local OpenAI-compatible fake that streams reasoning, text, two parallel tool calls (glob, bash), a slow bash call, a final answer, a forced 400 error, then /compact. Pane captures:

Before, and this branch with timestamps unset (identical after normalizing durations, at every stage):

  ┃  run the steps
     + Thought: 1.1s
     Looking around first.
     ✱ Glob "*" (1 match)
  ┃  $ echo hello
  ┃  hello
     + Thought: 139ms

"timestamps": "all", with a stale {"timestamps":"hide"} in kv.json:

  ┃  run the steps
  ┃  8:04 PM
     + Thought: 8:05 PM · 359ms
     Looking around first.
     8:05 PM
     ✱ Glob "*" (1 match) · 8:05 PM · 500ms
  ┃  $ echo hello
  ┃  hello
  ┃  8:05 PM · 666ms
     ▣  Build · Fake · 8:05 PM
  ┃  QA forced failure
  ┃  8:05 PM
  ──────────── Compaction · 8:05 PM ────────────

"timestamps": "user, tool": prompt times plus tool rows only. /timestamps hid the prompt times for that run and did not write kv.json.

Screenshots / recordings

Text captures above.

Checklist

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

[github-actions]

The following comment was made by an LLM, it may be inaccurate: