Model a versioned territorial domain D3

[sudoantonio]

Objective

Add a third semantic domain for territory without mixing territorial need with
the legal-subject profile.

Acceptance criteria

• D3 types and identifiers are documented and versioned.
• Indicators include source, reference period, geography and missing-data state.
• Trans-domain rules distinguish eligibility geography from policy priority.
• A fixture demonstrates reproducible entity-call-territory matching.