Wires customer_accounts.billing_email into the invoice, Storno, and
payment-reminder send paths. Previously the column existed on the
schema and the customer-detail page rendered an input for it, but no
send path read it — every outbound email landed on customer_accounts.email
regardless. That mismatch is the failure mode flagged in
feedback_data_driven_completeness: a UI field that promises behavior
the backend silently doesn't deliver.
Routing matrix:
- invoice / Storno / payment reminder
To: billing_email (fallback email when unset)
CC: email (when billing_email took the To slot) + per-doc cc_pdf_email
- quote / contract / event reminder / gallery share
To: email (unchanged — decision-maker address)
- payment-check / paid-notification
To: admin contact (unchanged — internal flow)
A new resolveBillingRecipients helper centralises the rules:
prefer billing_email, dedupe addresses case-insensitively, keep
per-doc cc_pdf_email as a supplemental CC. Lives in its own file
(_billingRecipients.js) to match the _renderContext.js convention.
Luca