Why: at the 3-per-conversation cap the guaranteed material task was dropped silently, and long deliverables stayed in chat because cardflow defaulted off (user ruling 2026-10-11).
Evidence: new queue lifecycle test (queued card, hard-reject for model path, FIFO start on release, card promote) passes; full go test ./... exit 0 (local, SELF).
Impact: queueable system spawns create a queued progress card at capacity and start FIFO when a slot frees (memory-only queue; restart limitation noted); model delegate_task still hard-rejects; ui.cardflow default true (EffectNewRun).
Refs: Dev task .task/feature-material-intake-flow.md I3.