Structured Contextual Distillation v4: Deployment Benchmarks and Artifact-Backed Evidence from 10 Months of AI State Management

This paper upgrades the Structured Contextual Distillation (SCD) v4 deployment report from a narrative field note into an artifact-backed systems paper. The underlying system, MirrorDNA, ran continuously from May 2025 through March 8, 2026 on a single Apple M4 Mac mini with 24 GB unified memory. The package includes rerunnable measurement scripts, 10 benchmark tables, redacted sample data, protocol schemas, and a claim ledger mapping every headline number to its evidence source.

We benchmark five aspects of the deployed state layer: event-store integrity, governance effectiveness, mutation integrity, cross-agent handoff envelopes, and context survivability under compaction pressure. The central claim: in deployed multi-agent AI systems, state becomes an identity layer only when it is temporal, governed, and continuously measurable.