GuardedResearchAgent: summarise has pre = "hasSources".

Topic "virtual threads": status COMPLETED, actions:
  com.ankurm.agents.embabel.GuardedResearchAgent.findSources
  com.ankurm.agents.embabel.GuardedResearchAgent.summarise
  com.ankurm.agents.embabel.GuardedResearchAgent.writeBrief
  LLM prompts: 2

Topic "quantum gravity": status STUCK, actions:
  com.ankurm.agents.embabel.GuardedResearchAgent.findSources
  LLM prompts: 0