Addresses the PR #763 review: the invoice_sent / storno_issued / payment-check
/ paid-admin-notification emails share the identical event-first language bug
and never set __language, so a German customer on an English-gallery event got
an English email body with German-formatted amounts.
Each call site already computes the locale it formats amounts in, so this is a
one-liner per call — the body language now matches the amount formatting:
- invoice_sent, storno_issued (sending.js) -> __language: ctx.locale
- payment-check, invoice_paid_admin_notification (payments.js) -> __language: locale
Leak-safe (no template references {{__language}}) and falls back to the
existing event-first resolution when unset, per the mechanism added in #763.
Luca
c0008be39b