C++17 Staged Toy Simulation for STA Pre-Commitment Controllability

This record is Paper 2 of the Signal-Time-Authority (STA) Series. Paper 2 provides staged C++17 synthetic toy-simulation evidence for the STA pre-commitment controllability framework introduced in Paper 1: https://doi.org/10.5281/zenodo.19980763 The report consolidates Stage 1 through Stage 8 results, including falsification, component ablation, revised ablation, boundary sensitivity, human latency thresholds, Safety Slack calibration, domain-specific deep runs, full STA-control ladder tests, and replication. The results support a narrow synthetic claim: STA control coupling has measurable control value in the toy benchmark, and harm-bounded policy choice matters. The report does not claim real-world validation, does not prove AI safety, and does not claim that the full ladder is universally best. This is a PublicRelease v1.0 record.