Add end-to-end session goals to Paperclip Runner
Add capability-aware slash-goal controls, durable provider goal state, PRP v2 negotiation, autonomous goal execution, and safe local session recovery. Integrate with current master, preserve provider session identity, and verify the browser goal/chat/replacement/clear workflow and unsupported-agent rejection.
Co-Authored-By: Paperclip <noreply@paperclip.ing>
