chore: update analytics to May 2026

[MillenniumFalconMechanic]

Ticket

Closes #4857

Summary

• Update CURRENT_MONTH to 2026-05 for HCA Explorer, AnVIL Explorer, and LungMAP
• Revert "Engaged Sessions" stat card back to "User Sessions" (total sessions) — the engaged sessions metric was too restrictive
• Fix "Cross-Dataset" → "Cross-Project" labels for HCA and LungMAP event counts and chart series
• Fix chart title bug where second chart in a pair used the first chart's label
• Port click_url_regex support into the shared analytics package for detail table file columns
• Make detail table file column header configurable via detail_file_column (defaults to "File")
• Add fileNameFromUrl helper to the shared template
• Simplify _count_events to use sequential DataFrame filtering instead of boolean mask accumulation
• Revert get_event_detail_table to vectorized pandas (remove iterrows)
• Regenerate all three static analytics sites with updated data

Test plan

• Regenerated and verified HCA Explorer locally
• Regenerated and verified AnVIL Explorer locally
• Regenerated and verified LungMAP locally

🤖 Generated with Claude Code

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[Copilot]

Pull request overview

Copilot reviewed 48 out of 51 changed files in this pull request and generated 7 comments.

[Copilot]

Pull request overview

Copilot reviewed 48 out of 51 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 48 out of 51 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 48 out of 51 changed files in this pull request and generated no new comments.