latest sleepqa

[joyan2]

Contributor: Jeffrey Yan
Contribution Type: Full Pipeline
Description: Implements the SleepQA dataset and an Extractive QA task, as well as a BioBERT + PubMedBERT pipeline.

Files to Review:

• pyhealth/datasets/sleepqa.py - Core dataset and indexing logic.
• pyhealth/datasets/configs/sleepqa.yaml - Table configuration.
• pyhealth/tasks/sleepqa_extractive_qa.py - Task definition and processor mapping.
• pyhealth/models/sleepqa_biobert.py - BioBERT model implementation.
• tests/core/test_sleepqa.py - Synthetic data test suite.
• pyhealth/datasets/init.py - Registry update.
• pyhealth/tasks/init.py - Registry update.