No Task Output

This prevents a sneaky context overflow issue where TaskOutput dumps entire agent transcripts (70k+ tokens) into your main conversation, triggering mid-conversation compaction and defeating the whole point of isolated agent contexts. It enforces using Task in synchronous mode instead, which keeps the agent work contained and just returns a summary. Born from an actual session where someone got bitten by this. If you're running background tasks and wondering why your context suddenly exploded, this is your guardrail. Simple rule, solves a real footgun.