Validate semantic correctness and guard against grain or schema drift.
Acceptance Criteria
Unit coverage:
- Seller-week grain enforcement
- Seller dimension grain enforcement
- Aggregation correctness (count/sum/mean)
- week_start_date derivation correctness
- Frozen schema validation (order + dtype)
- Duplicate key failure paths
- Stage executes via orchestrator
- Both semantic artifacts produced
- Deterministic output across repeated runs
Validate semantic correctness and guard against grain or schema drift.
Acceptance Criteria
Unit coverage: