BUG PLEXOR TEST: Agent halts mid-task requiring user nudge

Bug Bash - Plexor Agent Behavior

Severity: MEDIUM 🟡

Description:
During a bug fix session, the Plexor-routed agent halted after receiving Opus responses and required a user nudge to continue. The agent had identified the fix plan but stopped execution.

Timeline:

1. Agent was making edits with Haiku (~$0.028/request)
2. Routing escalated to Opus for unknown reason
3. Opus returned minimal output (9 tokens: "continue fixing the remaining input fields")
4. Agent halted - user had to nudge to continue
5. After nudge, routing returned to Haiku and edits continued

Possible Causes:

1. Opus response "continue fixing the remaining input fields" may have confused the agent
2. End_turn stop_reason on short responses may indicate premature completion
3. Context length (47 messages, 28K tokens) may have triggered unexpected behavior

Impact:

• User experience degraded - requires manual intervention
• Wasted $0.28 on Opus calls that didn't complete the task

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Found during real-time Plexor forensic analysis session.

@claude and @codex please review this pr