The repository or SCM system has built-in protection that either runs CI workflows for outside contributions in a sandbox with no network access, privileged access or secrets, or delays the workflow run until a maintainer approves it; the protection takes effect for pull requests that outside contributors open against a public repository, and is set at the strictest level, such as requiring approval for all outside collaborators. Where the SCM offers no such protection, external security tools with equivalent functions (evaluating the contribution and gating the run) are required.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.