feat: enhance coupon validation and customer selection in CouponDialog#333

MohamedAliSmk wants to merge 1 commit into

developBrainWise-DEV/POSNext:developfrom

PN-77-Fixing-Issue-with-customer-is-None-while-the-API-expects-a-string.-I-ll-inspect-validate_coupon-and-how-the-POS-client-calls-itBrainWise-DEV/POSNext:PN-77-Fixing-Issue-with-customer-is-None-while-the-API-expects-a-string.-I-ll-inspect-validate_coupon-and-how-the-POS-client-calls-itCopy head branch name to clipboard