- Added `range: string` to `connections_by_heritage_type` slot for better data representation.
- Removed obsolete `data_source_whatsapp`, `data_tier`, `date_retrieved`, and `de` slots from the schema.
- Updated `derived_from_observation` slot to support multiple values and changed range to `uriorcurie`.
- Introduced new `DataSource` class to represent various data sources with detailed descriptions and examples.
- Created `DataTierLevel` class to classify data quality tiers with standard codes and descriptions.
- Archived removed slots and updated the manifest to reflect these changes.
- Added new `was_retrieved_at` slot to track data retrieval timestamps, following RiC-O conventions.
