We plant eight small faults in platform/llm/byok.mjs and see whether its tests fail. Six did. Two slipped through: an explicit :80 on an Ollama host being rewritten to port 11434, and the 172.16.x to 172.19.x private range being dropped from the "nothing leaves your computer" check. The second matters, because a page only says data stays local when that check is true.
One new test covers both. Re-running the two escaped mutants against it, both are now caught, so the catch rate for this file went from 75% to 100%. No real defects turned up in the helper itself.