DND-1416: add optional azureblob regions (jclouds.regions) for bucket creation

The azureblob-sdk provider on real Azure needs jclouds.regions to create
buckets; without it `aws s3 mb` fails with InvalidLocationConstraint ("no
jclouds.regions configured for provider azureblob-sdk") — GH issue #15.

Add an optional config.backends.azureblob.regions value, emitted as
jclouds.regions= in the azureblob backend properties when set (omitted when
empty, so Azurite and other backends are unaffected).

This completes the chart mechanism for DND-1416 item 2. Items 1 (endpoint
typo) and 3 (default-endpoint guard) already landed via PR #22. The endpoint
fix + azureblob-sdk provider are confirmed against Azurite; the real-Azure
bucket-create fix (correct default region) still needs validation against a
live Azure backend.

No Chart.yaml version bump (deferred, handled separately), so verify-version
fails by design for now.

Verified on kind: azureblob-sdk + jclouds.regions round-trips against Azurite;
helm lint + kubeconform (all test-values) clean; regions omitted when empty.

Author: CRThaze

charts/s3proxy/templates/configmap.yaml

@@ -142,6 +142,11 @@ data:
   {{- if or .Values.config.backends.azureblob.endpoint .Values.config.backends.azureblob.account }}
     jclouds.endpoint={{ .Values.config.backends.azureblob.endpoint | default (printf "https://%s.blob.core.windows.net" .Values.config.backends.azureblob.account) }}
   {{- end }}
+  {{- if .Values.config.backends.azureblob.regions }}
+    # Required by the azureblob-sdk provider on real Azure to create buckets
+    # (otherwise "no jclouds.regions configured" -> InvalidLocationConstraint).
+    jclouds.regions={{ .Values.config.backends.azureblob.regions }}
+  {{- end }}
   {{- if .Values.config.backends.azureblob.account }}
     jclouds.identity={{ .Values.config.backends.azureblob.account }}
   {{- end }}

charts/s3proxy/values.yaml

@@ -226,6 +226,8 @@ config:
       # -- (string) Azure endpoint
       # @default -- `https://{{ .Values.config.backends.azureblob.account }}.blob.core.windows.net`
       endpoint:
+      # -- jclouds region(s) for the backend, emitted as `jclouds.regions=`. The azureblob-sdk provider requires this on real Azure to create buckets (without it `aws s3 mb` fails with InvalidLocationConstraint / "no jclouds.regions configured"). Comma-separated for multiple. Not needed against Azurite. Leave empty to omit.
+      regions: ""
       # -- SAS token configuration
       sasToken:
         # -- SAS token value