Commission Calculator

Build an internal tool for my team: "Commission Calculator".

The problem: Every month-end we spend two days arguing over the commission spreadsheet.
Who uses it: a team of 3–30 reps.

What it should do:
- Rep payouts: Each rep's earned commission for the period, with attainment against quota.
- Closed deals: Every deal, its rate, any accelerators or splits, and the resulting payout.
- Approve payouts: Finance signs off once, and the period locks so numbers stop moving.
- Plan rules: Tiers, accelerators and splits written down once instead of hidden in formulas.

Data:
- Rep { name, quota, plan_id }
- Plan { tiers[], accelerator_rate, split_rules }
- Deal { rep_id, value, closed_at, split_with? }
- Payout { rep_id, period, amount, approved_by?, approved_at? }

Constraints:
- Built for one team inside one company. Simple sign-in (or none), no billing, no multi-tenant setup.
- Fast, calm and obvious enough that teammates need zero training.
- Data must persist and be shared across the team.
- Ship the simplest version that works, then tell me what you'd add next.

Works with Claude, ChatGPT, Cursor, Lovable, Replit or Type.