fix: add auth health check

[arcoraven]

PR-Codex overview

This PR refines the healthCheck function in the src/server/routes/system/health.ts file to enhance the health check response structure and add authentication validation. It replaces the old response schema with a new one that includes database, Redis, and auth status.

Detailed summary

• Renamed ReplySchemaOk to ReplySchema.
• Removed ReplySchemaError and combined error handling into ReplySchema.
• Added db, redis, and auth boolean properties to the response.
• Implemented isAuthValid function to check authentication status.
• Updated response structure in healthCheck to include new properties.

✨ Ask PR-Codex anything about this PR by commenting with /codex {your question}

[zeet-co]

We're building your pull request over on Zeet.
Click me for more info about your build and deployment.
Once built, this branch can be tested at: https://tw-unreal-demo-engine-vwn0-ph-authhealth.engine-aws-usw2.zeet.app before merging 😉