V0: Annotation API - Annotation App Token Support

[emmyxth]

As per conversation https://github.com/MIT-LCP/physionet-build/issues/1047#issuecomment-3285413494, we want to add fine-grained token authorization. This PR introduces granular OAuth token scopes for the Annotations API, replacing the broad annotations:view and annotations:edit scopes with resource-specific permissions.

Changes

1. Fine-Grained OAuth Scopes (physionet/settings/base.py)

Replaced broad scopes with granular permissions:

• Collections: annotations:collections:read and annotations:collections:write
• Types: annotations:types:read and annotations:types:write
• Annotations: annotations:annotations:read and annotations:annotations:write

2. New Permission Classes (annotation/views.py)

• Added AnnotationsCollectionsScope for collection endpoints
• Added AnnotationsTypesScope for type endpoints
• Updated views to use resource-specific permission classes instead of generic AnnotationsScope

3. New Collection Read Endpoint (annotation/views.py, annotation/urls.py)

Added AnnotationCollectionReadAPIView with:

• GET endpoint at /annotations/collection/<slug>/
• Optimized queryset with prefetch_related() to reduce database queries
• Proper scope validation (annotations:collections:read)

4. Serializer Improvements (annotation/serializers.py)

• Moved AnnotationCollectionSerializer to end of file (after AnnotationSerializer definition)
• Added annotations field to AnnotationCollectionSerializer to include related annotations in collection responses
• Fixed AnnotationSerializer.to_representation() to properly access child location models:
  • instance.location.textspanlocation instead of instance.location
  • instance.location.timeseriesintervallocation instead of instance.location
  • instance.location.imagebboxlocation instead of instance.location

5. Updated Tests (annotation/tests.py)

• Added _read_annotation_collection() helper method
• Updated all tests to use new granular scopes
• Added test_read_annotation_collection_correct_scope() to verify collection read endpoint with proper scope handling

All existing tests updated and passing with new scope requirements. New test added for collection read endpoint.