Graduated STA Control: Authority Governors and Runtime Deployment Architecture

This record is Paper 3 of the Signal-Time-Authority (STA) Series. Paper 3 specifies the runtime deployment architecture for the STA pre-commitment controllability framework introduced in Paper 1: https://doi.org/10.5281/zenodo.19980763 It complements the staged C++17 synthetic toy-simulation evidence reported in Paper 2: https://doi.org/10.5281/zenodo.19984104 This paper focuses on authority governors, non-bypassable commitment gates, pre-registered pi_STA policies, sandboxing, rollback, fallback routing, bypass testing, hysteresis, human override policy, and audit-log requirements. This is a PublicRelease v1.0 record.