Use when the user says "buying signals", "intent data", "trigger events", "job change alerts", "we get signals and nothing happens", "is this intent data worth it", "signal monitoring", "hiring triggers". Builds a signal taxonomy with decay windows, dedup, severity thresholds, and an explicit signal-to-play routing table. Includes the backfill discrimination test for vendor renewal. Writes workspace/data/signal-taxonomy.csv.
