Add PUF tax detail support and batched fiscal reform scoring

[MaxGhenis]

Summary

• add PUF tax-detail support imputation for the US support channel, including PUF-only writeback tests
• add a general --maximum-microsim-batch-size release-builder option and batch tax-expenditure reform microsim materialization by household slice
• align the deductible-mortgage-interest JCT tax-expenditure row to neutralize the tax-unit interest_deduction input that actually flows into itemized deductions in this dataset

Local validation

• uv run ruff check tools/build_us_fiscal_refresh_release.py packages/populace-build/src/populace/build/us/puf_support.py packages/populace-build/src/populace/build/us/__init__.py packages/populace-build/tests/test_us_fiscal_refresh_builder.py packages/populace-build/tests/test_us_fiscal_targets.py packages/populace-build/tests/test_us_puf_support.py
• uv run python -m json.tool packages/populace-build/src/populace/build/us/fiscal_target_references.json >/dev/null
• uv run --package populace-build --extra us pytest packages/populace-build/tests/test_us_fiscal_refresh_builder.py packages/populace-build/tests/test_us_puf_support.py (58 passed)
• uv run --package populace-build --extra us pytest packages/populace-build/tests/test_us_fiscal_targets.py (50 passed)

Local diagnostic build

Built the PUF-support base H5 at out/puf-support-local-20260619/base/base_populace_us_2024_puf_support.h5 and ran a full target-surface 128-epoch calibration with --maximum-microsim-batch-size 25000.

Result diagnostics: out/puf-support-local-20260619/calibrated-128-batched-r2/releases/populace-us-2024-puf-support-local-128-batched-r2-20260619/calibration_diagnostics.json.

Metrics:

• records: 150,224 households
• targets: 4,356
• initial loss: 0.08174028247594833
• final loss: 0.041313028782942386
• within 10%: 0.8686868686868687

This is not release-valid yet. Remaining hard gate failures:

• Social Security benefits: -12.1156% relative error
• Premium Tax Credit amount: +12.0435% relative error

The mortgage-interest JCT target is no longer zero-support: it materializes at $33.61B final against a $24.8B target after the interest_deduction mapping change.

Review

Read-only cycle review reported no actionable findings. Residual risk: this branch overlaps active fiscal-refresh PRs (#121, #128, #130), so merge order may require follow-up reconciliation.