Done. I've written the assumption register review to `output/register-note.md`. The review identifies 4 flagged assumptions across the 20-assumption register:

- **2 stale reviews**: Inventory turns (last reviewed March) and line of credit interest rate (last reviewed June) both exceed the 180-day threshold.
- **1 unowned**: Merit increase has no owner assigned.
- **1 unsourced change**: Headcount increased from 23.00 to 23.75 FTE with no source recorded, and feeds the headcount driver.

Of the 5 changed assumptions overall, headcount's lack of source needs immediate clarification. The two stale assumptions are ready for their owners to review, and the merit increase needs an owner assigned before the plan locks.