=== ROUTER STEP FACTS CONTRACT VALIDATION ===
step=STEP_044L_ACTIVITY_SAMPLER_SCHEMA_CONTRACT_CLOSE_READONLY
decision=PASS
all_ok=True
structure_ok=True
success_ok=True
expected_absence_ok=True
blockers_ok=True
success_checks_count=33
expected_absence_count=12

warnings:
  - STEP_044L is read-only and applies no migration.
  - Existing columns last_tx_* and last_rx_* are sufficient as sampler baselines.
  - Next step can implement a one-shot DB sampler update using this exact mapping.