EPIC-P2-02 Catalog Canonicalization + Mapping

[madhavcodez]

Objective

Build canonical catalog/provider mapping foundation for provider-limited import.

Scope

• Canonical IDs and provider IDs contracts
• Mapping pipeline with confidence and conflict handling

Acceptance Criteria

• Child tasks P2-02.1/02.2/02.3 complete and linked
• Mapping confidence model and fallback behavior documented