Predict likely bug hotspots with three Agent SDK subagents

Notes & tips

• Depend on the documented public surface. The supported API is BugPredictionWorkflow (its constructor and async execute) plus the WorkflowResult it returns. Names with a leading underscore — the pattern helpers in bug_predict_patterns.py and _run_agent_predict — are internal and may change.
• format_bug_predict_report and main were removed. They consumed the pre-v4.2.0 dict pipeline shape (overall_risk_score, patterns_found, …), not the WorkflowResult that execute returns, and had no live caller once the SDK-native rewrite shipped. Read result.final_output (a WorkflowReport when subagent findings parsed as structured output, rendered via attune.voice.report_renderer.render()) and result.summary directly instead.
• Start shallow, then deepen. Run quick to triage, and only spend a deep budget on the modules that came back hot.
• Use --cheap for routine CLI runs. It forces unpinned subagents onto Haiku, trading some depth for cost.