Cross-environment schedule deduplication clarified

Guidelines for scheduled tasks are clarified to prevent cross-environment collisions. Using identical deduplication keys across staging and production overwrites existing schedules, as the keys are scoped per project rather than per environment.

The documentation outlines new mitigation strategies. For fixed schedules, declarative cron tasks are recommended. When imperative scheduling is required across environments, environment names should be appended directly to the deduplication keys. This update in the scheduled tasks documentation prevents accidental production overwrites during testing.