Mentor hour reports now export to CSV and XLSX

What's new

• One-click Export button in the mentor hours table.
• Filter first (cohort, mentor, program, date range) then export — the file mirrors exactly what's on screen.
• Two formats: CSV for ingestion into a spreadsheet or BI tool, XLSX with pre-formatted columns ready to send to a sponsor.

Why it matters

Quarterly sponsor reports were one of the last places teams were still copy-pasting cells. Self-serve exports save program managers about an afternoon per quarter and make the underlying data more auditable.