Azure Blob Storage - Target Directory and DisableMakeDirectories=true

Current Situation

• If an AzureBlobStorageFragment is configured as a target with DisableMakeDirectories=true:
  • YADE transfer fails with a Blob Storage account where Hierarchical Namespace is disabled, regardless of whether the target directory actually exists.
  • e.g.:

    YADEEngineException: [Target][DisableMakeDirectories=true][yade/yade-engine-test] directory does not exist and automatic creation is disabled

• Background
  • An Azure Blob Storage account can be configured with Hierarchical Namespace (HNS) enabled or disabled.
    • HNS enabled:
      • Real directories with hierarchical namespace and directory operations.
      • Directory handling should work, but this is currently not tested.
    • HNS disabled
      • Flat namespace. Directories are virtual blob-name prefixes.
      • YADE currently uses the HTTP 404 status code to determine whether a directory exists.
      • With HNS disabled, this check always returns 404 because virtual directories are not separate resources.

Desired Behavior

• The directory existence check should work correctly for Azure Blob Storage accounts with HNS disabled.