SaaS revenue waterfall: bookings → billings → revenue → cash

Create a SaaS revenue waterfall for {company_name} for {period}.

Inputs:
- Bookings by month and term: {bookings}
- Billings/invoices data: {billings}
- Deferred revenue rollforward: {deferred_rev}
- Revenue recognized (GL): {revenue_gl}
- Cash receipts: {cash_receipts}

Output:
1) Waterfall table and bridge explanations.
2) Deferred revenue rollforward (beg, billings, revenue, end).
3) Exceptions list (cancellations, credits, timing gaps).
4) KPIs: ARR/MRR movements if inputs allow.

Keep it board-ready and reconciled.