aisman

Session 127, Step 23: AffiliateLedger row not created when discount code applied to purchase
- AIM-2400 AffiliateLedger row not created when discount code applied to purchase
- AffiliateNickname uniqueness: check against other nicknames and discount codes
- Discount code uniqueness: additionally check against AffiliateNickname fields
- Add UI for AffiliateDiscountCode.RDCIsDefault on /affiliate pages with single-default enforcement
- Rename table AffilianteDiscountCode to AffiliateDiscountCode (typo fix)
- Slug routes /{slug} and /pricing/{slug} redirect to /pricing with discount code auto-filled