buildInvoiceAttachment() extracted out of sendOrderConfirmationEmail() so
sendPaymentSwitchedEmail() can reuse the same invoice-PDF generation
instead of duplicating it — the invoiceNumber stays the same, but
paymentMethodTitle now reflects the confirmed instrument, which flips
the PDF's own paid/unpaid display, so re-attaching a fresh copy matters
here even though nothing else about the order changed.
Default fallback copy replaced with brand-toned wording matching the
existing order-confirmation fallback's voice, instead of a flat
system-notice tone.
Marco
18f5156fd8