[backend] - Add comprehensive request/response logging

[Hydrax117]

Location: backend/src/middleware/logging.rs

No detailed request logging for debugging.

Acceptance Criteria:

• Log all HTTP requests
• Include headers (sanitize auth)
• Log response status and latency
• Structured JSON logs
• Log rotation policy

[MarcusDavidG]

@MarcusDavidG has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I can handle this issue and will like to work on it, Please assign thank you.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @MarcusDavidG to this issue.