Add structured audit logging for all admin actions

[sshdopey]

What

Admin score updates only emit console.log lines with no structured format. There is no audit trail for who triggered updates, when, or with what parameters.

Why

Compliance and forensics require structured audit logs. Without them, there is no way to investigate unauthorized or accidental score changes.

Scope

• Create a dedicated audit logger (separate from application logs)
• Log: timestamp, action, requester IP, user agent, project IDs, results
• Output to a dedicated audit log file or stream
• Include request correlation IDs

Acceptance Criteria

• Audit log entry for every POST /api/admin/update-scores call
• Entry includes: timestamp, action, IP, user agent, project IDs, success/failure
• Audit log is separate from application logs
• Entries are JSON-structured for parsing

Technical Context

• src/routes/admin.ts:48,50,57 — current console.log calls
• New file: src/lib/audit.ts or similar
• Could use a separate log file or a dedicated stream

[Mistersmile4585]

@Mistersmile4585 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I'm a Full Stack Software Engineer with experience building scalable web and mobile applications. I enjoy solving problems, learning quickly, and contributing to meaningful projects. I will be glad if this issue is assigned to me

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Mistersmile4585 to this issue.

[drips-wave]

Congratulations, @Mistersmile4585! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on August 31, 2026.

🧑‍💻 @Mistersmile4585: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

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