chore(deploy): rework k8s pipeline, monitoring and postgres 17

Deploy workflow uses git-tracked manifests, DISABLED flag and kustomize overlays; add webinar-checker metrics with ServiceMonitor and alerts; upgrade shared postgres to 17 with statuspage DB and probes/resources.

edu_master/k8s/playwright.yaml

@@ -17,7 +17,8 @@ spec:
     spec:
       containers:
         - name: playwright
-          image: mcr.microsoft.com/playwright:v1.63.0-jammy
+          # renovate: datasource=docker depName=mcr.microsoft.com/playwright versioning=docker
+          image: mcr.microsoft.com/playwright:v1.56.0-jammy
           imagePullPolicy: IfNotPresent
           command:
             - npx