feat: close preprod observability loop

deploy/observability/prometheus/rules/socialize-alerts.yml

@@ -11,6 +11,16 @@ groups:
           summary: Socialize API telemetry is missing
           description: No API request telemetry has been received for 5 minutes. The API or telemetry pipeline may be down.
 
+      - alert: SocializePreprodEndpointDown
+        expr: probe_success{job="preprod-uptime"} == 0
+        for: 2m
+        labels:
+          severity: critical
+          service: socialize-preprod
+        annotations:
+          summary: Preprod endpoint is down
+          description: '{{ $labels.instance }} has failed blackbox checks for 2 minutes.'
+
       - alert: SocializeApiHighErrorRate
         expr: |
           (
@@ -56,6 +66,26 @@ groups:
           summary: Socialize core usage is quiet
           description: No content, comment, approval, or feedback activity has been observed over the last 12 hours.
 
+      - alert: SocializeContentStaleInApproval
+        expr: socialize_workflow_stale_in_approval > 0
+        for: 30m
+        labels:
+          severity: warning
+          service: socialize-api
+        annotations:
+          summary: Content is stale in approval
+          description: One or more content items have been in approval longer than the configured threshold.
+
+      - alert: SocializeNoActiveWorkspaces
+        expr: socialize_workflow_active_workspaces{window="24h"} < 1
+        for: 1h
+        labels:
+          severity: info
+          service: socialize-api
+        annotations:
+          summary: No active workspaces in the last 24 hours
+          description: No workspace has content workflow activity in the last 24 hours.
+
       - alert: SocializeFeedbackBugSubmitted
         expr: sum(increase(socialize_feedback_submitted_total{feedback_type="Bug"}[15m])) > 0
         for: 0m