Carry US candidate filing status and pinned scoring guard

[MaxGhenis]

Summary

• map microunit filing_status_input back into PE-readable is_surviving_spouse and is_separated inputs during US candidate export
• carry CPS SSI-disability evidence into required meets_ssi_disability_criteria, without exporting forbidden ssi_reported
• default candidate scoring to the certified pinned production eCPS blob
• reject the known local enhanced_cps_2024_hf_main.h5 baseline to avoid non-promotion-valid scorer runs

Validation

• uv run ruff format --check scripts/build_us_candidate.py tests/test_build_us_candidate.py
• uv run ruff check scripts/build_us_candidate.py tests/test_build_us_candidate.py
• git diff --check
• uv run --extra dev python -m pytest tests/test_build_us_candidate.py tests/test_packs_us.py (12 passed)
• smoke export passed at /Users/maxghenis/.codex-worktrees/microplex-holdout-support-triage-20260610/artifacts/spec_candidate_smoke_filing_status_20260610 (candidate_timeperiod.h5 cols=257, missing=0, gate passed=true, defaulted=187, dropped=0)
• smoke export passed at /Users/maxghenis/.codex-worktrees/microplex-holdout-support-triage-20260610/artifacts/spec_candidate_smoke_ssi_disability_20260610 (candidate_timeperiod.h5 cols=257, missing=0, gate passed=true, defaulted=186, dropped=0; meets_ssi_disability_criteria true count=878, ssi_reported absent)

No full candidate was scored or promoted in this PR.