A scheduled engineering agent job ran green for weeks while silently doing nothing. An agent that reports an ECO as processed while the PLM write silently failed is a manufacturing defect waiting to happen, and nothing in the status channel distinguishes done from never-started.
From the 2026-10-07 pain-radar digest (finding 23): the original post is a software scheduling job (digest-secondary), so the ECO/PLM framing is extrapolated, hence Low confidence. Included because the pattern, ran green versus worked, is the central validation gap for engineering agents and the community's own fix (heartbeat rows, canary records) is hand-built per team.