Clarify request logging with nested req/res fields

[dillonstreator]

Summary

• Nest request logging under req / res with clear field names (pino-http style)
• Replace cryptic abbreviations (ua, br, bw) with userAgent, bytesRead, bytesWritten
• Use responseTime for duration in milliseconds; bind request id as req.id

Test plan

• Run pnpm test and confirm existing suites pass
• Hit an endpoint and verify the finish log looks like { req: { id, method, path, userAgent, ip, bytesRead }, res: { statusCode, bytesWritten }, responseTime }
• Confirm request-scoped logs (e.g. /hi) still include req.id