feat: add batch date-range filters

What does this MR do and why?

This MR adds date-range filtering support for Batch Mode analytics in the GitLab Compliance Checker.

✨ Changes introduced

• Added support for --from and --to inputs (format: YYYY-MM-DD) in batch workflows

• Implemented robust validation with clear user-facing error messages

• Converted parsed dates into timezone-aware (IST) start and end timestamps

• Wired validated date range into GitLab API calls for:

  • Commits
  • Merge Requests
  • Issues

• Ensured backward compatibility when date range is not provided

🎯 Why this change?

Previously, batch analytics processed lifetime activity only. This enhancement enables:

• Focused time-window analysis
• Better mentor and team insights
• Improved hackathon evaluation workflows
• Consistent behavior with single-user analytics

This is part of the Contributions Mapping over Selected Date Range feature.

---

References

• Hackathon GitLab-API enhancement
• Related branch: feat-date-range-mapping

---

Screenshots or screen recordings

before After