Replace manual negative income targets with SOI controls

[MaxGhenis]

Summary

• Remove the rough hard-coded negative household market income amount/count controls from the legacy loss matrix.
• Add SOI all-return negative AGI amount/count targets and positive-valued taxable SOI loss-component AGI-bin targets.
• Wire the same loss-component targets into the DB/new calibration path and default target config.

Target shape

• 2024 get_soi selects 2023 negative AGI rows, uprated to about -$150.6B and 2.20M returns.
• Adds 134 positive-valued taxable loss-component AGI-bin targets across business, capital gains, estate, partnership/S-corp, and rent/royalty losses.

Tests

• uv run ruff check policyengine_us_data/utils/loss.py policyengine_us_data/db/etl_irs_soi.py tests/unit/calibration/test_loss_targets.py tests/unit/test_etl_irs_soi_overlay.py tests/unit/calibration/test_target_config.py
• uv run pytest tests/unit/calibration/test_loss_targets.py tests/unit/test_etl_irs_soi_overlay.py tests/unit/calibration/test_target_config.py