feat(vso): deploy Vault Secrets Operator; add test RBAC + amd64 image aliases

- Add base/vso/ with Helm chart (v0.9.0 from helm.releases.hashicorp.com),
  namespace, and test-rbac.yaml granting the Helm test pod's default SA
  permission to create/read/delete Secrets, ConfigMaps, and Leases so the
  bundled connectivity test passes.
- Wire ../../base/vso into overlays/local/kustomization.yaml.
- Add image aliases for lasuite/people-backend and lasuite/people-frontend
  so kustomize rewrites those pulls to our Gitea registry (amd64-only images
  that are patched and mirrored by sunbeam.py).

base/vso/namespace.yaml

@@ -0,0 +1,6 @@
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: vault-secrets-operator
+  annotations:
+    linkerd.io/inject: disabled