Analyze this test failure and produce a structured bug report.

Failure Details:
{failure_details}

Similar Past Bugs (RAG context):
{rag_context}

Return a JSON object with exactly these fields:
- title: short descriptive bug title
- severity: one of Critical, High, Medium, Low
- priority: one of P1, P2, P3, P4
- failure_signature: short identifier for this failure type (e.g. NoSuchElementException_login_button)
- root_cause: explanation of root cause
- root_cause_confidence: confidence in root cause analysis (0.0 to 1.0)
- fix_suggestion: suggested fix
- fix_confidence: confidence in fix suggestion (0.0 to 1.0)
- severity_confidence: confidence in severity assessment (0.0 to 1.0)

Return ONLY valid JSON, no markdown.
