Problem

Currently, we expose license state metrics (coderd_license_active_users, coderd_license_limit_users, coderd_license_user_limit_enabled) but we don't have specific metrics for license warnings or errors that could help with monitoring and alerting.

Proposed Solution

Add Prometheus metrics to track license warnings and errors:

• coderd_license_warnings - Gauge (1 = warning active, 0 = no warning)
• coderd_license_errors - Gauge (1 = error active, 0 = no error)

Implementation Notes

• Extend the existing license.MetricsCollector in /enterprise/coderd/license/metricscollector.go
• Hook into the entitlement warning system that already exists (WriteEntitlementWarningHeaders)
• Consider adding labels for different types of warnings/errors

Benefits

• Better observability for license issues
• Proactive alerting on license problems
• Historical tracking of license health