Declare translatable post metadata

Extend pom_translate_translatable_meta_keys with post-type-specific metadata configuration:

add_filter(
    'pom_translate_translatable_meta_keys',
    static function ( array $config ): array {
        $config['product'][] = 'acme_public_badge';
        return $config;
    }
);

Preserve existing keys and return an array. Register only public textual metadata whose complete value can be translated safely.

Do not include IDs, prices, stock, booleans, serialized builder state, private fields, tokens, or relationship keys. Nested structures require a schema-aware adapter; adding their top-level meta key does not make arbitrary serialization safe.

The post type must also have metadata translation enabled. Save the object after registering the key so extraction sees the source value, then verify frontend and REST behavior.