3. Scheduled Task Contract

Enable scheduler only when the application registers bounded local work:

Cargo.toml

[dependencies]
appcore-sdk = { version = "1.0.0-rc.2", features = ["scheduler"] }

Implement Application::register_tasks with ApplicationTaskRegistry, ScheduledTask, TaskSchedule, and an explicit retry policy. The callback performs one bounded unit of work and returns a controlled result.

The application owns the callback and task identity. The selected deployment owns scheduler workers, concurrency, retry timing, cancellation, supervision, and shutdown. Never start a detached thread or endless loop inside a callback.

Test duplicate identities, zero intervals, retry idempotency, admission during shutdown, and callback failure. Durable multi-step workflows remain outside the process-local scheduler profile.

Next: change deployment mode without changing business code.