Function render_template 

pub async fn render_template(
    ctx: &ScriptCtx,
    source: &str,
) -> Result<TransactionDraft, TemplateError>

Renders source for ctx’s user, returning the accumulated draft. Runs the program form-by-form under the render linker (read-only financial natives + draft natives only). The final value of each form is ignored; only the draft side effects matter.