PhoenixKitWeb.Components.AITranslate.FormBinding for catalogue forms —
the storage-specific half of the shared AI-translate glue.
Catalogue stores translations in the multilang data JSONB via
PhoenixKit.Utils.Multilang, with per-language overrides under
underscore-prefixed keys (data[lang]["_name"]). The engine speaks
plain field names, so apply_translation/4 re-prefixes before writing and
force-stores even values equal to the primary (so an untranslatable string
still fills the field instead of looking like a failed translation).