Discrepancy between absolute and relative decile impacts at the constituency level

[MaxGhenis]

See https://policyengine.org/uk/policy?focus=policyOutput.distributionalImpact.incomeDecile.relative&reform=92846&region=constituency%2FChelsea+and+Fulham&timePeriod=2025&baseline=1&uk_local_areas_beta=true

cc @nikhilwoodruff @anth-volk in case this is an API / policyengine.py issue

[MaxGhenis]

Closing on the UK repo because this discrepancy is downstream, not in the UK country package itself. The policyengine-uk model only produces national income deciles; region-scoped decile, budget, poverty, inequality, and labor-supply report outputs are assembled downstream. The mismatch appears in policyengine-api compare_economic_outputs and is then labeled as if it were constituency-scoped in policyengine-app-v2. No safe fix belongs in policyengine-uk for this issue.