TextractServiceTest:
  ✓ Constructor with default region
  ✓ Constructor with custom region
  ✓ analyzeDocument returns structured response
  ✓ analyzeDocument returns false with invalid credentials
  ✓ analyzeDocumentFull returns structured response
  ✓ parseTables handles empty response
  ✓ parseTables extracts table from response
  ✓ parseTables includes row data and confidence