10.1% of agent config files are exact cross-repo duplicates.

A prevalence study of 10,008 public GitHub repos found 10.1% of tracked agent config paths (rules files, agent definitions, CLAUDE.md-style markdown) are SHA-256 exact duplicates across independent repos, with 75.5% of clone pairs near-identical. Agent configurations are propagating as undeclared, unmanaged shared dependencies. The authors propose a deterministic control plane to version and audit them. If you maintain steering files, treat them like dependencies, not loose docs.