Implement Item History Service to Sync 'current_location'

[vivjd]

Goal:
Implement logic to keep CollectionItem.current_location and is_on_floor synced with history.

Tasks:

• Implement compute_current_location(item_id) helper
• Update current location when relevant events occur
• Add maintenance command to rebuild all locations

Acceptance Criteria:

• Location updates correctly on history change
• Rebuild command yields consistent results