fix: roundtable max_iterations 3→9 for 3-agent, 3-round deliberation

With 3 agents and max_iterations=3, effective_max=max(3,3)=3, meaning
each agent speaks exactly once per roundtable — no back-and-forth.
Adjudicator correctly rejected these as incomplete (score=0-58 on
completeness/consensus_clarity/actionability).

9 iterations = 3 full rounds for 3 agents, allowing genuine debate:
Round 1: Initial assessments | Round 2: Responses | Round 3: Consensus

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

templates/chapter_roundtable.yml

@@ -24,7 +24,7 @@ steps:
   - type: think
     rotate_participants: true
     loop:
-      max_iterations: 3
+      max_iterations: 9
     hint: |
       You are {agent.name}, an editor in the editorial roundtable for this chapter.
       {agent.identity}