• Replace truthy checks with `is not None`
• Handle empty dict edge case properly
• Prevent data reload failures
• Add comprehensive test coverage
• Fix JsonKVStorage and DocStatusStorage
• Reload cleaned data after sanitization
• Update shared memory with clean data
• Add specific surrogate char tests
• Test migration sanitization flow
• Prevent dirty data in memory
- Fast path for clean data (no sanitization)
- Slow path sanitizes during encoding
- Reload shared memory after sanitization
- Custom encoder avoids deep copies
- Comprehensive test coverage
