Fix issue #194: [Claude] Refactor picture_creation

[cld-vasconcelos]

This pull request fixes #194.

The issue has been successfully resolved based on the concrete changes made:

1. The original monolithic picture_creation function was effectively broken down into three focused helper functions:

• _get_user: Handles user lookup
• _process_image_file: Handles image processing and validation
• _create_picture_object: Handles picture object creation

2. The refactoring directly addresses the core requirements:

• Each new function has a single, clear responsibility
• Variable names are more descriptive (e.g., image_bytes, filename)
• Complex logic is simplified by separating concerns
• Code duplication is eliminated
• The overall behavior remains unchanged while improving readability

3. A comprehensive test suite was added that verifies:

• Successful picture creation flows
• Error handling for invalid users
• File size validation
• Maintaining existing functionality

4. The code quality is improved through:

• Added type hints
• Clear docstrings for each function
• More Pythonic code practices (using isinstance())
• Better error handling structure

The changes directly solve the original maintainability and readability issues while preserving functionality, as evidenced by both the code changes and the new test coverage. The refactored code is now more modular, easier to understand, and simpler to maintain - meeting all the stated requirements of the issue.

Automatic fix generated by OpenHands 🙌