Create scheduled/cron Trigger.dev v4 tasks with schedules.task, including declarative crons, per-tenant imperative schedules and timezones

Documented steps

1. Define the task with `schedules.task`: `import { schedules } from "@trigger.dev/sdk"; export const dailyTask = schedules.task({ id: "daily-task", run: async (payload) => {...} });` (https://trigger.dev/docs/tasks/scheduled).
2. Inside `run`, read `payload.timestamp`, `payload.lastTimestamp`, `payload.timezone` (IANA), `payload.scheduleId`, `payload.externalId` and `payload.upcoming` (next 5 run times).
3. For a fixed schedule declared in code, add `cron: { pattern: "0 5 * * *", timezone: "Asia/Tokyo", environments: ["PRODUCTION", "STAGING"] }` to the task definition — it syncs on `dev` or `deploy`.
4. For dynamic/multi-tenant schedules create them at runtime: `await schedules.create({ task: dailyTask.id, cron: "0 0 * * *", timezone: "America/New_York", externalId: "user_123", deduplicationKey: "user_123-reminder" });`
5. Validate user-supplied timezones against `await schedules.timezones()`.
6. Manage schedules with `schedules.retrieve`, `schedules.list`, `schedules.update`, `schedules.activate`, `schedules.deactivate`, `schedules.del`.
7. Test the task from the dashboard Tasks page via "Test schedule" with custom payload values before relying on it.