Add request/response debug logging

[codebestia]

Description

When debugging integration issues, developers need visibility into what the SDK is sending and receiving. A debug mode should log outgoing requests (method, URL, headers, body) and incoming responses (status, headers, body), with sensitive values masked.

Proposed Steps

• Add debug: bool = False to ShadeClient and global config.
• When debug=True, emit structured logs via Python's logging module under the shade logger.
• Mask Authorization header value in logs (show only last 4 characters).
• Truncate response bodies longer than 2000 characters with a [truncated] suffix.

Acceptance Criteria

• With debug=True, each request logs method, URL, and masked headers.
• Each response logs status code and truncated body.
• Authorization header value is always masked in logs.
• With debug=False (default), no request/response content is logged.
• Logs use logging.DEBUG level so they don't appear unless the app enables them.

[isaacCodes1]

Hi, I'd like to work on this issue. I've gone through the description and acceptance criteria and I'm confident I can deliver it. I'll make sure every acceptance criterion is met and submit a clean, tested PR. Please assign it to me.

[Oluwasuyi-Timilehin]

Hi! I came across this issue and would love to work on it. I have experience with similar tasks and I'm confident I can investigate, implement a clean solution, and thoroughly test it before submitting a PR. If the issue is still open, I would appreciate it if you could assign it to me. Thank you!

[grantfox-oss]

🦊 GrantFox — @isaacCodes1 has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #13)
2. Your PR will be reviewed by the ShadeProtocol maintainers

Good luck! Track your progress on GrantFox.