Covers the steering channel: ordered delivery, the start-of-run reset so an old run's answers never replay, dropping malformed or forged entries (half-written handoffs, unsafe surface names, empty messages), the Merge instruction round-tripping, and the repo-wide guard that no runtime state under the framework's directory is tracked in git.

## Before writing SPEC.md files

Read https://raw.githubusercontent.com/brillout/sdd/refs/heads/main/sdd.md
