Draft: Port selected loss.py targets into unified calibration

[anth-volk]

Branch: codex/add-loss-py-targets-unified

Context

Legacy policyengine_us_data/utils/loss.py still contains calibration target families that were not selected by the newer unified calibration target set. We audited the legacy target families against policyengine_us_data/calibration/target_config.yaml and identified a narrow set that are distinct from existing unified targets, were not recently removed by Max Ghenis, and are not just slight variants of already-selected targets.

What this branch does

This branch ports the recommended target families into unified calibration:

• Adds SOI taxable AGI-grid income targets for:
  • irs_employment_income, mapped from SOI employment_income, matching the legacy loss.py concept.
  • pension_income, mapped from SOI total_pension_income.
  • social_security, mapped from SOI total_social_security.
• Selects existing IRS workbook target rows for:
  • refundable American Opportunity Credit amount and claimant count.
  • nonrefundable education tax credit amount and claimant count.
• Adds state EITC claimant-count targets from IRS EITC Central controls.
• Selects state SNAP household-count targets already loaded by SNAP ETL.
• Selects LIHEAP household-count targets already loaded by national target ETL.
• Adds and selects state ACS rent targets from acs_housing_costs_YEAR.csv.
• Selects positive real-estate-tax itemizer count targets nationally and by state.
• Adds and selects Medicare Part B premium age-bucket targets from healthcare_spending.csv.

Files touched

• policyengine_us_data/calibration/target_config.yaml
• policyengine_us_data/db/create_field_valid_values.py
• policyengine_us_data/db/etl_irs_soi.py
• policyengine_us_data/db/etl_national_targets.py
• tests/unit/calibration/test_target_config.py
• tests/unit/test_etl_irs_soi_overlay.py
• tests/unit/test_etl_national_targets.py

Verification so far

Passed locally:

• python3 -m py_compile policyengine_us_data/db/etl_irs_soi.py policyengine_us_data/db/etl_national_targets.py policyengine_us_data/db/create_field_valid_values.py tests/unit/test_etl_irs_soi_overlay.py tests/unit/test_etl_national_targets.py tests/unit/calibration/test_target_config.py
• ruff check policyengine_us_data/db/etl_irs_soi.py policyengine_us_data/db/etl_national_targets.py tests/unit/test_etl_irs_soi_overlay.py tests/unit/test_etl_national_targets.py tests/unit/calibration/test_target_config.py
• git diff --check

Blocked locally:

• uv run pytest tests/unit/test_etl_irs_soi_overlay.py tests/unit/test_etl_national_targets.py tests/unit/calibration/test_target_config.py

The pytest command is blocked on this macOS x86_64 environment because the lock currently resolves torch==2.9.1, which has no wheel for this platform.