Hybrid routing by difficulty and privacy

Workflow: 1) Classify: Predict task difficulty and sensitivity. 2) Route: Simple tasks to small local models; complex to frontier models. 3) Cache: Share results where safe; invalidate on context changes. 4) Fallback: Retry on failure; escalate to human if uncertainty remains. 5) Observe: Track per-route quality and cost; auto-tune thresholds. 6) Governance: Log routing decisions for audits. Cuts cost 30-60% without hurting quality when tuned carefully.