fix(typescript): Fix cron expression in JSDoc to avoid parse error

Changed cron expression from '0 0 */6 * *' to '0 0,6,12,18 * * *'
to avoid TypeScript parser confusion. The '*/' sequence was being
interpreted as the end of a JSDoc comment, causing parse errors.

Verification:
- TypeScript compiles ✅
- Build passes ✅

src/definitions.ts

@@ -636,7 +636,7 @@ export interface DailyNotificationPlugin {
    * const schedule = await DailyNotification.createSchedule({
    *   id: 'daily-fetch',
    *   kind: 'fetch',
-   *   cron: '0 0 */6 * *',
+   *   cron: '0 0,6,12,18 * * *',
    *   enabled: true
    * });
    * ```