0.5

Mirrors modelq python 1.0.11 fixes for production stuck-task and queued_requests leak.

• worker_loop: persist startedAt on the Task object and write status='processing' on task:{id} so storeFinalTaskState keeps them.
• requeueStuckProcessingTasks: fall back to queued_at when started_at is missing. Covers workers killed in the sAdd processing_tasks → setex task:{id} window.
• storeFinalTaskState: zRem queued_requests on terminal state. Stops unbounded zset growth.