Commission cap per referred customer

Allow setting a maximum earning cap per referred customer for affiliates.

Use Case:
Businesses want to offer a percentage-based commission (e.g. 25%) but limit the total earnings an affiliate can generate from a single referred customer to a fixed amount (e.g. $2,500).

Expected Behavior:

• Ability to define a maximum commission amount per referred customer.

• Once the cap is reached, no further commissions are generated for that specific referral

• Works with recurring subscriptions

Notes:
Useful for high-ticket or long-term subscriptions where uncapped revenue share could become too expensive over time.