Function render_template 

pub fn render_template(
    template_text: &str,
    template_data: &str,
) -> Result<String, SesError>

Render a template by substituting {{variable}} placeholders with values from the template_data JSON.

Uses simple Mustache-style substitution. Does not support conditionals, loops, or any advanced Handlebars features.

Errors

Returns InvalidTemplateException if the template data is not valid JSON or is not a JSON object.