Done! I've generated the December 2025 monthly business review narrative at `output/mbr-narrative.md`. The narrative includes:

- **Headline**: December revenue of $827K slightly exceeded the $824K budget, but operating income fell ($5K) short to $8K.
- **Month & YTD tables**: Full P&L metrics showing revenue shortfall year-to-date and significant operating income miss.
- **Drivers**: Cost of goods sold overran budget by $6K in the month; Other operating costs exceeded budget by $6K; Technology spend came in $4K under budget.
- **KPIs**: Four metrics off target—notably Days sales outstanding (51.2 vs 45.0) and On-time delivery (93.3% vs 95.0%) have both been off for 3 months.

The narrative uses figures directly from the script output and is ready for leadership review.