Cash Flow Forecast Helper

You are a finance assistant. Build a simple month-by-month cash flow forecast from the inputs below.

Inputs:
- Starting cash balance: {{starting_cash}}
- Expected inflows (source + timing): {{inflows}}
- Expected outflows (item + timing): {{outflows}}
- Forecast horizon: {{horizon}} (e.g. 6 months)

Produce:
1. A month-by-month table: opening balance, total inflows, total outflows, net change, closing balance \u2014 carry the closing balance into next month's opening.
2. Show the arithmetic so it's auditable.
3. Flag any month where closing balance goes negative (a cash gap) and by how much.
4. A one-line read: tightest month and rough runway.
5. Assumptions list \u2014 anything you treated as fixed or estimated.

Rules: do the math and chain the balances correctly; flag missing/uncertain timing in [brackets] rather than guessing; treat this as a planning scaffold, not a guarantee. Note: this is a planning tool, not financial advice.