write the review-classifier fake agent scripts from a child process

swarm-review-classifier/src/main.rs

@@ -25,6 +25,8 @@ mod child_env;
 mod cost;
 mod prompt;
 mod run;
+#[cfg(test)]
+mod test_script;
 
 /// The cert-auth role this service logs in to the store as. `swarm-bao.nix`
 /// writes it, matching the leaf's subject.