feat: show full agent routing table after swarm completes

[acreeger]

Summary

• Hook reads epic loom state from metadata on UserPromptSubmit events when ILOOM_SWARM=1
• If state is done or failed (swarm finished), injects full agent routing table with iloom-swarm-* prefixed agents
• If swarm is still running, shows existing minimal code reviewer reminder
• Orchestrator prompt adds Step 5.5 to call set_loom_state with done on the epic after printing the swarm summary

Test plan

• Run a swarm to completion and verify follow-up prompts show the full routing table
• Verify prompts during an active swarm still show only the minimal reminder