[codex] Harden DiffScope review operations #408

Job	Run time
security	28s
lint	1m 20s
Coverage (llvm-cov)	1m 41s
mutation	15m 23s
test (ubuntu-latest)	1m 37s
version	4s
test (windows-latest)	3m 36s
cargo-deny (advisories + licenses)	24s
test (macos-latest)	1m 37s
	26m 10s

Provide feedback