Add primary_residence_value and derive assessed_property_value from assessment rates

[daphnehanse11]

Background

Property tax reform PRs need a data-backed property value signal. assessed_property_value currently exists as a person-level input, but policyengine-us-data cannot honestly populate it from ACS VALP because VALP is market/property value, not assessed value.

Proposed work

• Add primary_residence_value as a person-level yearly USD input.
• Convert assessed_property_value from a raw input into a formula based on primary_residence_value and state assessment-rate parameters.
• Add assessment-rate parameters for states needed by the active property tax PRs.
• Preserve zero values for renters and non-owner households.
• Document clearly that ACS VALP is property/market value, not assessed value.

Acceptance criteria

• primary_residence_value is available as an input variable.
• assessed_property_value can be calculated from primary-residence value and state parameters.
• Property tax PRs can consume the derived assessed value without asking policyengine-us-data to mislabel ACS VALP.

Related tracking

Part of the policyengine-us-data master tracking issue to data-back property value for property tax modeling.