fix(argocd): wire missing SOPS CMP plugin sidecar on repo-server, add grafana-admin secret

Sidecar container was absent from live repo-server Deployment (never in
helm history), causing sops-secrets Application to fail with cmp-server
socket not found — cascaded CreateContainerConfigError across every app
depending on SOPS-decrypted secrets. Also fixes duplicate version field
in plugin ConfigMap that produced a mismatched socket filename, and adds
an initContainer to fetch the sops binary into a writable emptyDir since
the sidecar runs non-root. grafana-secrets.enc.yaml rewritten from a bare
values file (never valid as a K8s Secret) to a proper Secret manifest so
grafana-admin now actually gets created.

k8s/bootstrap/phase4-argocd/argocd-values.yaml

@@ -54,6 +54,61 @@ repoServer:
       operator: Exists
       effect: NoSchedule
 
+  # Fetch sops binary into shared emptyDir (runs as root; main containers can't write /usr/local/bin)
+  initContainers:
+    - name: install-sops
+      image: alpine:3.20
+      command: [sh, -c]
+      args:
+        - |
+          wget -qO /sops-bin/sops https://github.com/getsops/sops/releases/download/v3.9.3/sops-v3.9.3.linux.amd64
+          chmod +x /sops-bin/sops
+      volumeMounts:
+        - mountPath: /sops-bin
+          name: sops-bin
+
+  # SOPS CMP sidecar (decrypts *.enc.yaml via argocd-cmp-cm ConfigMap plugin)
+  extraContainers:
+    - name: sops-secrets-v1
+      command: [/var/run/argocd/argocd-cmp-server]
+      image: quay.io/argoproj/argocd:v3.4.5
+      env:
+        - name: SOPS_AGE_KEY_FILE
+          value: /sops-age/key.txt
+        - name: PATH
+          value: /sops-bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+      volumeMounts:
+        - mountPath: /var/run/argocd
+          name: var-files
+        - mountPath: /home/argocd/cmp-server/plugins
+          name: plugins
+        - mountPath: /tmp
+          name: cmp-tmp
+        - mountPath: /home/argocd/cmp-server/config/plugin.yaml
+          subPath: sops-secrets-v1.0.yaml
+          name: argocd-cmp-cm
+        - mountPath: /sops-age
+          name: sops-age
+          readOnly: true
+        - mountPath: /sops-bin
+          name: sops-bin
+          readOnly: true
+      securityContext:
+        runAsNonRoot: true
+        runAsUser: 999
+
+  volumes:
+    - name: sops-bin
+      emptyDir: {}
+    - name: cmp-tmp
+      emptyDir: {}
+    - name: argocd-cmp-cm
+      configMap:
+        name: argocd-cmp-cm
+    - name: sops-age
+      secret:
+        secretName: sops-age
+
 # Controller configuration
 controller:
   resources: