Run3 Data Processing and JSON Serialization

When processing the data, implement the following logic:

1. Time-to-Merge Calculation:
   • Filter for items where mergedAt is not null.
   • Use jq to compute the difference between createdAt and mergedAt in seconds, divide by 86400, and calculate the average.
   • Apply round or map to ensure the float has one decimal place.
2. Bug Report Filtering:
   • Use any or contains within jq to filter labels: any(.labels[]; .name | contains("bug")).
3. Empty State Handling:
   • Use the // coalesce operator in jq to default empty values to 0 or null to ensure the report.json structure remains strictly valid even if no data exists for a category.
4. Validation:
   • Pipe the final result through jq '.' to verify that the generated JSON matches the required schema before writing to /app/report.json.