Summary

Ensure every relative age display (e.g. 2 weeks ago) shows the absolute date and time in the browser timezone on hover.

Current behavior

• Relative ages are rendered with DateUtils.formatAge() (PrettyTime + UI locale).
• Absolute datetimes are rendered with DateUtils.formatDateTime() as yyyy-MM-dd HH:mm in the session zone (browser timezone from Intl.DateTimeFormat().resolvedOptions().timeZone).
• Many places already expose that absolute value on hover via title or data-tippy-content (issue/PR detail and activities, issue/PR/code-comment lists, contributor dates, etc.).

Gaps (relative age without absolute hover tooltip)

• Build list date column (BuildListPanel)
• Build side panel submit/retry dates (BuildSidePanel)
• Package list publish date (PackListPanel)
• Package side panel publish date (PackSidePanel)
• Workspace list create date (WorkspaceListPanel)
• Workspace data last-modified (WorkspaceDataPanel)
• Build artifacts last-modified (BuildArtifactsPage)
• Folder view last-commit age (LastCommitsResource / folder-view.js)
• Comment history / revision titles (CommentHistoryLink, CommentRevisionPanel)
• Blame / markdown commit age displays (BlameMessageBehavior, MarkdownViewer) where only relative age is shown

Expected behavior

1. Hovering a relative age shows the absolute datetime in the user's browser timezone.
2. Prefer Tippy (data-tippy-content) for consistency with the pull request list; native title is acceptable where Tippy is not already used.
3. Keep the existing yyyy-MM-dd HH:mm format from DateUtils.formatDateTime().

Acceptance criteria

•  All DateUtils.formatAge() UI surfaces listed under Gaps show absolute datetime on hover
•  Absolute value uses browser timezone (same as existing formatDateTime() / session zone handling)
•  Existing places that already have hover absolute datetime keep working

Related question: #2906