acs-local: weekly_hours_worked_before_lsr defaults to 40, silently nulling SNAP ABAWD analysis

Reported by @TheDavidTrimmer in Slack (#microcosm-us, 2026-08-24), with the full trace — filing so the fix has a tracking home.

Defect: on the acs-local builds (populace-us-2024-buildp-acs-local-592ae5d6…), weekly_hours_worked_before_lsr arrives ~96% defaulted: the gate summary shows it missing for 3.4M of 3.6M ACS-spine persons, and the engine default fills 40 hours. The SNAP ABAWD work-requirement test reads this variable, and 40 clears both the 20- and 30-hour thresholds — so every affected person looks compliant and the OBBBA work-requirement counterfactual silently returns ~$0. No error is raised.

Trace (David's): hours_worked_last_week in the same file is real (mean ~17, 54% zeros), so the signal exists; the _before_lsr leaf specifically isn't transferred. acs_transfer.py skips it as a runtime-owned leaf; the seeding stage wants ASEC columns the ACS-spine persons don't have; and us_hours_worked_signal_gate — which would have caught this — is not wired into the local finalize gates. The national stacked-spine pool is unaffected because #578 already QRF-transfers weekly_hours_worked_before_lsr from ASEC HRSWK; that transfer was never extended to the local-area lane.

Impact: blocks the state + congressional-district SNAP work-requirement analysis (Daniel Kim's paper). An interim proxy (override with hours_worked_last_week, corr 0.97 but ~20% high in levels) is fine for exploration, not publication. policyengine-us#9261 already flipped the engine default 40→0, so the remaining work is pipeline-side.

Fix scope:

1. Extend the #578 ASEC-HRSWK hours transfer to the local-area builder.
2. Wire us_hours_worked_signal_gate into the local finalize gates so a defaulted hours column can never ship quietly again.
3. A regression that fails the local lane on a defaulted weekly_hours_worked_before_lsr.

🤖 Filed by the microcosm owner session with Claude Code

Start in acs_transfer.py and trace the #578 ASEC-HRSWK transfer from the national stacked-spine path into the local-area builder. Then inspect the local finalize gates and the existing us_hours_worked_signal_gate. Done means the local lane transfers weekly_hours_worked_before_lsr, the gate is wired, and a regression fails when that column is defaulted.