semantic exchange layer structuring -- flattened but object oriented, linked to full schema modules and classes

[realmarcin]

include both the flat (core/exchange layer) slots and the extended/structured version, ensuring each slot supports both flat and extended representations

[realmarcin]

This issue is addressed by PR #129 which implements the semantic exchange layer with both flat and structured representations.

The PR includes:

• Flattened exchange layer (core slots)
• Extended/structured version (full schema modules and classes)
• Bidirectional transformation support

Related PR: #134 adds slot_uri definitions that enable semantic linking between D4D attributes and standard vocabularies.

[realmarcin]

📝 Update: PR #134 Merged ✅

The slot_uri definitions from PR #134 have been merged, providing URI mappings needed for semantic linking.

Current Status:

• ✅ Slot_uri coverage: 46.3% (125/270 attributes)
• ⏳ Semantic exchange layer implementation: Waiting for PR Add semantic exchange layer for D4D ↔ RO-Crate transformations #129

This issue will be fully resolved when PR #129 (which implements the flat + structured representations) is also merged.