[Feature Request] Add optional per-message timestamps to transcript UI

Feature Description
Add per-message timestamps to the transcript UI in claude code cli, right-aligned and dimmed,
for both user and Claude messages. The timestamp field is already on every
entry in the session JSONL — it's just not rendered. Long sessions have no
temporal context at all. Opt-in via settings.json would be ideal.

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.1.220
• Feedback ID: 680583b3-90ca-46a6-8681-7d4a45273a3b

Errors

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