Any plans for FixDelayTask

### Things to check first

- [x] I have searched the existing issues and didn't find my feature already requested there

### Feature description

It currently supports tasks of the cron expression type and fixed-rate type. However, fixed-delay tasks are not yet supported (where a fixed interval elapses between the end of one task execution and the start of the next). Do you have any plans to implement this feature?

### Use case

For large-batch task scheduling, we aim to process as many tasks as possible in each run cycle. When there are no pending tasks, the system will sleep for a fixed period and then wake up to check again for executable tasks.

Start by reading the scheduler entry points for cron-expression and fixed-rate tasks, then trace how task timing is represented and advanced after execution. Compare those paths with the requested fixed-delay semantics, where the interval begins after a task finishes. Done means the project has a defined API and behavior for fixed-delay scheduling, including the large-batch polling use case.

Written by the indexing model from the issue text.