CI as Oracle

When an agent has no local build/test toolchain, remote CI becomes the sole authoritative verifier, so every change must ship reversibly and auto-revert if CI later fails.

grounded in: doctrine principles.md VERIFY layer: 'A local compiler is absent, so the Rust build is checked only in CI — treat that as the source of truth and be ready to revert', enforced by the loop's auto-rever