feat: Add debug logging for file_path conflict resolution

Added debug logging when resolving file_path conflicts in upsert_entity
to track how often the conflict resolution path is hit in production.
This will help with monitoring and debugging sync operations.

Logs entity_id, file_path, and observation count when merge is used.

Signed-off-by: phernandez <paul@basicmachines.co>

Author: phernandez

src/basic_memory/repository/entity_repository.py

@@ -3,6 +3,7 @@
 from pathlib import Path
 from typing import List, Optional, Sequence, Union
 
+from loguru import logger
 from sqlalchemy import select
 from sqlalchemy.exc import IntegrityError
 from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker
@@ -163,6 +164,10 @@ async def upsert_entity(self, entity: Entity) -> Entity:
 
                 if existing_entity:
                     # File path conflict - update the existing entity
+                    logger.debug(
+                        f"Resolving file_path conflict for {entity.file_path}, "
+                        f"entity_id={existing_entity.id}, observations={len(entity.observations)}"
+                    )
                     # Use merge to avoid session state conflicts
                     # Set the ID to update existing entity
                     entity.id = existing_entity.id