Use authorization block and metrics-token secrets in ServiceMonitors

[tamalsaha]

Summary

• replace deprecated bearerTokenFile usage with ServiceMonitor authorization credentials blocks
• add per-chart long-lived ServiceAccount token Secret templates (type: kubernetes.io/service-account-token)
• use Secret names with the -metrics-token suffix: -metrics-token
• wire ServiceMonitor credentials to key token in the corresponding metrics token Secret

Why

Prometheus Operator rejects ServiceMonitor specs that use bearerTokenFile. This updates charts to the supported credentials-based auth style and avoids filesystem token references.

Charts Updated

• stash-community
• stash-enterprise
• stash-ui-server

Notes

• no new template helper added
• commit is signed off (DCO)