SSR dashboard: new errors-and-hit-rate tile fed by /__stats samples in vitec:ssr-health (stat_* columns in healthlog)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

packages/vitec/Configuration/Services.yaml

@@ -51,3 +51,14 @@ services:
         iconIdentifier: 'content-widget-number'
         height: 'medium'
         width: 'medium'
+
+  Evomedien\Vitec\Widgets\SsrErrorsWidget:
+    tags:
+      - name: dashboard.widget
+        identifier: vitecSsrErrors
+        groupNames: systemInfo
+        title: 'VITEC: SSR errors & hit rate'
+        description: 'Render/backend error counters and cache hit rate of the SSR node (/__stats, sampled every 5 minutes)'
+        iconIdentifier: 'content-widget-list'
+        height: 'medium'
+        width: 'medium'