Map IRS SOI state broad Arch targets

[MaxGhenis]

Summary

• map newly productionized Arch IRS SOI state broad concepts into Microplex target variables
• cover qualified dividends, tax-exempt interest, Schedule C, partnership/S-corp, and medical/dental expense concepts
• add a focused JSONL provider regression test for these state broad SOI mappings

Validation

• uv run ruff check src/microplex_us/targets/arch.py tests/targets/test_arch_facts.py
• uv run pytest tests/targets/test_arch_facts.py::test_arch_consumer_fact_jsonl_provider_maps_state_broad_soi_concepts -q
• uv run pytest tests/targets/test_arch_facts.py -q

Coverage artifact

Using merged Arch PR #18 plus these mappings, PE-native broad coverage is 106/189 cells. Persisted at /Users/maxghenis/CosilicoAI/microplex-us/artifacts/arch_soi_state_broad_coverage_20260528/pe_native_broad_2024_coverage.json.

Stacked on #9.