Fill missing current CD targets from state totals

[MaxGhenis]

Summary

• synthesize source-vintage CD proxy facts from matching SOI state facts when a crosswalk source state has a single statewide/at-large source geography and no SOI source-CD facts
• limit proxying to shapes already present in true SOI source-CD facts, including SOI return universe, to avoid state-only target expansion
• update the CD hierarchy completeness profile to all 436 current 119th Congress districts, including one-district states and DC

Validation

• uv run --python 3.13 --package populace-build --group dev python -m pytest packages/populace-build/tests/test_us_congressional_district_vintage.py packages/populace-build/tests/test_us_congressional_district_geography.py packages/populace-build/tests/test_us_fiscal_targets.py packages/populace-build/tests/test_us_fiscal_refresh_builder.py packages/populace-build/tests/test_us_puf_support_base_builder.py -q
• uv run --python 3.13 --package populace-build --group dev ruff check packages/populace-build/src/populace/build/us_runtime/congressional_district_vintage.py packages/populace-build/tests/test_us_congressional_district_vintage.py packages/populace-build/tests/test_us_fiscal_targets.py packages/populace-build/src/populace/build/us_runtime/fiscal_targets.py tools/build_us_fiscal_refresh_release.py tools/build_us_puf_support_base.py
• python3 -m json.tool packages/populace-build/src/populace/build/us/fiscal_target_references.json >/dev/null && git diff --check
• Real Ledger/crosswalk compile: 33,127 total specs; 24,776 CD specs; 436/436 current 5001900US geographies; no old-prefix CD specs; 56 SOI CD measure IDs
• Translated support distribution: 436 rows across 51 jurisdictions; no missing/extra current CD geoids

Review cycle

• First subagent review found mixed-source suppression, confounded double-counting test, and SOI universe matching gaps.
• Fixed all three, reran focused checks, and second subagent review reported no actionable findings.