- Customer entity + DTO: new BillingEmail field (accounting/invoicing address)
- Email fields now accept comma-separated lists; DTO validates each address individually
- NotificationService: SendToEmailListAsync helper fans out to all addresses in a list;
NotifyQuoteSentAsync accepts optional overrideEmail so staff can send to an ad-hoc address
- Migration: AddCustomerBillingEmail
- Customer Create/Edit/Details views updated to show Billing Email field
- customer-billing-email.js: client-side helpers for billing email input
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
spouliot