Release v0.1.1

Bug fixes

• Fix POS store-credit balance deductions when WCPOS sends signed or zero-value coupon line discounts to StoreApps Smart Coupons.
• Normalize POS smart-coupon usage to positive StoreApps smart_coupons_contribution values so coupon balances decrease instead of staying unchanged or increasing.
• Infer zero-value POS coupon line usage from order-level discounts or reduced order totals only when the store-credit allocation is unambiguous.
• Avoid over-deducting ambiguous mixed-coupon orders and POS orders with negative fee/manager discount lines.

Tests

• Expanded regression coverage for real StoreApps balance updates.
• Added coverage for positive, negative, and zero POS coupon discounts.
• Added coverage for mixed regular coupons, zero-amount non-store coupons, tax mode differences, ambiguous multi-coupon cases, and negative POS fees.