Fix RedisVL API compatibility issue in memory retrieval

- Handle both old and new RedisVL API formats for search results
- Old API: results.docs, New API: results is directly a list
- This fixes AttributeError: 'list' object has no attribute 'docs'
- Real integration issue caught by proper testing instead of mocks

Author: abrookins

python-recipes/context-engineering/reference-agent/redis_context_course/memory.py

@@ -142,7 +142,9 @@ async def retrieve_memories(
 
         # Convert results to ConversationMemory objects
         memories = []
-        for result in results.docs:
+        # Handle both old and new RedisVL API formats
+        docs = results.docs if hasattr(results, 'docs') else results
+        for result in docs:
             if result.vector_score >= similarity_threshold:
                 memory = ConversationMemory(
                     id=result.id,