fix: use correct health handlers

[Flo4604]

What does this PR do?

Replaces the basic health check endpoint with separate liveness and readiness probes for the sentinel service. The liveness probe continues to use the simple health endpoint, while the readiness probe now includes database connectivity and middleware engine status checks.

Adds a PingContext method to the database replica to support connection health verification.

Updates Kubernetes probe configurations to use distinct endpoints: /_unkey/internal/health/live for liveness and /_unkey/internal/health/ready for readiness.

Fixes #5367

Type of change

• Bug fix (non-breaking change which fixes an issue)
• Chore (refactoring code, technical debt, workflow improvements)
• Enhancement (small improvements)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How should this be tested?

• Verify the liveness probe endpoint /_unkey/internal/health/live returns 200 OK
• Verify the readiness probe endpoint /_unkey/internal/health/ready returns 200 OK when database and engine are healthy
• Test that readiness probe fails when database connection is unavailable
• Test that readiness probe fails when middleware engine is not ready
• Confirm Kubernetes probes work correctly with the new endpoint paths

Checklist

Required

• Filled out the "How to test" section in this PR
• Read Contributing Guide
• Self-reviewed my own code
• Commented on my code in hard-to-understand areas
• Ran pnpm build
• Ran pnpm fmt
• Ran make fmt on /go directory
• Checked for warnings, there are none
• Removed all console.logs
• Merged the latest changes from main onto my branch with git pull origin main
• My changes don't cause any responsiveness issues

Appreciated

• If a UI change was made: Added a screen recording or screenshots to this PR
• Updated the Unkey Docs if changes were necessary

[Flo4604]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• fix: use correct health handlers #5376 👈 (View in Graphite)
• fix: retry redis conn in the bg and fail open otherwise #5377
• feat: add sentinel prom metrics #5283
• feat: add prometheus metrics for frontline routing and proxy #5268
• fix: instance-aware frontline routing to prevent 503s in regions without instances #5267
• main

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Project	Deployment	Actions	Updated (UTC)
dashboard	Ready	Preview, Comment	Mar 24, 2026 1:23pm

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