Hypothesis Writer

Write a structured A/B test hypothesis for the following:

Change Description: {{change_description}}
Target Audience: {{target_audience}}
Expected Outcome: {{expected_outcome}}
Primary Metric Type: {{metric_type}}

Return ONLY valid JSON matching this exact schema (no markdown, no code fences):
{
  "hypothesis": {
    "statement": "We believe [change] for [audience] will result in [outcome] because [rationale]",
    "rationale": "detailed explanation of why this change should work",
    "primaryMetric": "the single most important metric to measure success",
    "secondaryMetrics": ["metric1", "metric2", "metric3"],
    "minimumDetectableEffect": "e.g. '5% lift in conversion rate'",
    "suggestedDuration": "e.g. '2-3 weeks'",
    "risks": ["risk1", "risk2", "risk3"]
  }
}