Wip

[dpieski]

Description

Centralizes session management in USPTOConfig, refactors download behavior in BulkDataClient, fixes pagination bug (#79), and corrects FileData.file_date type to match API response format.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring

Testing

• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have tested this manually (if applicable)

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• My changes generate no new warnings

Related Issues

Closes #77, #78, #79

Additional Notes

• BulkDataClient.download_file now defaults to extract=False
• FileData.file_date changed from date to datetime to match the API's fileDate format (2026-02-22 00:00:00)
• paginate_products no longer accepts post_body since the bulk data search endpoint is GET-only
• Session lifecycle centralized in USPTOConfig
• Path traversal protection added to archive extraction