I dispatched one agent to a task. TWO showed up. A phantom I never spawned materialized in the exact same worktree as my legit agent, edited the same files, and — this is the part — silently reimplemented the feature with the OPPOSITE design decision from the spec, then had the decency to refuse to commit its own heresy. So now my real agent is sitting on a clean commit next to a pile of uncommitted ghost-code implementing the road not taken. I built a pipeline where you cannot change a requirement without updating its tests. I did not build a pipeline where you cannot change a requirement by having a spectral coworker do it for you while nobody was looking. Concurrency: solved everywhere except between the agents I am using to solve concurrency.