[FEATURE]: desktop: option to show message send timestamps in the session transcript #62857

Feature hasn't been suggested before.

• I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

Version: OpenCode Desktop 2.2.0 on Windows 10 (10.0.19045); also checked the released tags up to 2.2.6.

Problem

The Desktop transcript shows no send time for any message, and there is no setting for it. Settings → Timeline covers detail level, width, background activity, and changed files — but not timestamps.

What exists today (checked in the sources of 2.2.0–2.2.6):

• User messages: no time is rendered anywhere in any released tag. On the dev branch the chevron menu now shows the send time (the sent() memo in message-content.tsx: "Today/Yesterday, HH:mm", then date + time), but reading it requires opening a menu for each message.
• Assistant messages: only the turn duration is shown (turnDurationMs), never wall-clock time.

When reading a long session afterwards, timestamps are the main missing chronology anchor: the transcript communicates what happened and how long turns took, but not when.

Desired behavior

An opt-in setting (e.g. Settings → Timeline → "Show message timestamps") that renders each message's send time inline — for example a small locale-short time next to the message meta line, for both user and assistant messages, or subtle time markers between turns / day separators.

The data is already available (message.time.created), so this is purely a presentation option.

Related

• [FEATURE]: Show completion time and duration for every assistant turn in the TUI #53192 asks for completion time per assistant turn in the TUI (PR feat(tui): add configurable reply timestamps #62530 adds session.timestamps / session.date_format to cli.json). This request is the Desktop counterpart, and also covers user messages.
• [FEATURE]: Desktop: user message hover timestamps should include the date, not just the clock time #44936 asked for dates in the user-message hover timestamps; the chevron-menu time on dev resolves that, but inline always-visible time would serve readers who scan the transcript rather than open messages one by one.

Timestamps would stay useful in the new Timeline detail presets: in "Quiet" / "Messages only" modes messages remain visible while activity is hidden, and timestamps keep the chronology readable there too.