Threadmoth: a deterministic, source-preserving mutation boundary for AI coding agents

I kept seeing the same failure in AI-assisted coding: the agent chose the right change, then applied it through an improvised mix of sed, regex replacement, patches, one-off scripts, direct writes, or whole-file rewrites. The problem is not that those tools are bad. The problem is that each path has different rules for ambiguity, stale state, preservation, failure, and evidence. The agent is left responsible for deciding whether the final write was safe. So I built Threadmoth, a small Rust CLI