Fix ArgoCD ServerSideDiff permanent OutOfSync diffs

Add explicit CRD/API defaults to manifests that were causing ArgoCD's
SSA dry-run to produce results different from live state:

- HTTPRoutes: add group, kind, weight defaults to parentRefs/backendRefs
- Kyverno ClusterPolicies: add skipBackgroundRequests, allowExistingViolations
- Tetragon TracingPolicies: add return, maxData, resolve, returnCopy defaults
- Gateway certificateRefs: add group="" default
- Guacamole Gateway: add group="" to certificateRefs

Add ignoreDifferences for resources that legitimately differ:
- Cilium cert Secrets (auto-generated, data always differs)
- Istio ValidatingWebhookConfiguration failurePolicy (istiod mutates)
- Crowdsec LAPI Secrets (randomly generated)
- ServiceMonitor/PodMonitor relabeling action defaults
- StatefulSet volumeClaimTemplates apiVersion/kind defaults

Persist argocd-cm ignoreDifferences config in ArgoCD Helm values.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

argocd-apps/infrastructure/crowdsec.yaml

@@ -9,6 +9,12 @@ metadata:
     - resources-finalizer.argocd.argoproj.io
 spec:
   project: infrastructure
+  ignoreDifferences:
+    - group: ""
+      kind: Secret
+      name: crowdsec-lapi-secrets
+      jsonPointers:
+        - /data
   sources:
     - repoURL: https://crowdsecurity.github.io/helm-charts
       chart: crowdsec