/**
 * Replaces `{key}` placeholders in a copy string with values from `vars`.
 * Missing keys leave the placeholder intact so broken templates stay visible in UI/tests.
 */
export const format = (template: string, vars: Record<string, string | number>): string =>
  template.replace(/\{(\w+)\}/g, (match, key: string) => {
    const value = vars[key]

    return value === undefined || value === null ? match : String(value)
  })