feat(orchestrator): multi-storage support for GCP and Azure providers

Both providers now support four storage backends via gcpStorageType / azureStorageType:

GCP Cloud Run:
  - gcs-fuse: Mount GCS bucket as POSIX filesystem (unlimited, best for large sequential I/O)
  - gcs-copy: Copy artifacts in/out via gsutil (simpler, no FUSE overhead)
  - nfs: Filestore NFS mount (true POSIX, good random I/O, up to 100 TiB)
  - in-memory: tmpfs (fastest, volatile, up to 32 GiB)

Azure ACI:
  - azure-files: SMB file share mount (up to 100 TiB, premium throughput)
  - blob-copy: Copy artifacts in/out via az storage blob (no mount overhead)
  - azure-files-nfs: NFS 4.1 file share mount (true POSIX, no SMB lock overhead)
  - in-memory: emptyDir tmpfs (fastest, volatile, limited by container memory)

New inputs: gcpStorageType, gcpFilestoreIp, gcpFilestoreShare, azureStorageType,
azureBlobContainer. Constructor validates storage config and warns on missing
prerequisites (e.g. NFS requires VPC connector/subnet).

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

action.yml

@@ -291,12 +291,33 @@ inputs:
     description:
       '[Orchestrator] [Experimental] Google Cloud region for Cloud Run Jobs (e.g. us-central1).
       Defaults to the region input if empty.'
+  gcpStorageType:
+    required: false
+    default: 'gcs-fuse'
+    description:
+      '[Orchestrator] [Experimental] Storage type for Cloud Run Jobs. Options:
+      gcs-fuse (mount GCS bucket as filesystem, unlimited size, best for large sequential I/O),
+      gcs-copy (copy artifacts in/out via gsutil, simpler, no FUSE overhead),
+      nfs (Filestore NFS mount, true POSIX, good random I/O, up to 100 TiB),
+      in-memory (tmpfs, fastest but volatile, up to 32 GiB).'
   gcpBucket:
     required: false
     default: ''
     description:
       '[Orchestrator] [Experimental] GCS bucket name for build artifact storage.
-      Mounted via GCS FUSE for large filesystem support.'
+      Used by gcs-fuse and gcs-copy storage types.'
+  gcpFilestoreIp:
+    required: false
+    default: ''
+    description:
+      '[Orchestrator] [Experimental] Filestore instance IP address for NFS storage type.
+      Required when gcpStorageType is nfs.'
+  gcpFilestoreShare:
+    required: false
+    default: '/share1'
+    description:
+      '[Orchestrator] [Experimental] Filestore share name for NFS storage type.
+      Defaults to /share1 (the Filestore default).'
   gcpMachineType:
     required: false
     default: 'e2-standard-4'
@@ -306,8 +327,8 @@ inputs:
     required: false
     default: '100'
     description:
-      '[Orchestrator] [Experimental] Disk size in GB for Cloud Run Jobs. Supports up to 32GB
-      in-memory or unlimited via GCS FUSE bucket mount.'
+      '[Orchestrator] [Experimental] Disk size in GB for Cloud Run Jobs in-memory volumes.
+      Only applies to in-memory storage type (max 32).'
   gcpServiceAccount:
     required: false
     default: ''
@@ -330,18 +351,32 @@ inputs:
     description:
       '[Orchestrator] [Experimental] Azure region for Container Instances (e.g. eastus, westeurope).
       Defaults to the region input if empty.'
+  azureStorageType:
+    required: false
+    default: 'azure-files'
+    description:
+      '[Orchestrator] [Experimental] Storage type for Azure Container Instances. Options:
+      azure-files (SMB file share mount, up to 100 TiB, premium throughput),
+      blob-copy (copy artifacts in/out via az storage blob, no mount overhead),
+      azure-files-nfs (NFS 4.1 file share mount, true POSIX, no SMB lock overhead),
+      in-memory (emptyDir tmpfs, fastest but volatile, size limited by container memory).'
   azureStorageAccount:
     required: false
     default: ''
     description:
-      '[Orchestrator] [Experimental] Azure Storage Account name for file share mounting.
-      Uses Premium FileStorage for high-throughput large artifact I/O.'
+      '[Orchestrator] [Experimental] Azure Storage Account name.
+      Used by azure-files, azure-files-nfs, and blob-copy storage types.'
   azureFileShareName:
     required: false
     default: 'unity-builds'
     description:
       '[Orchestrator] [Experimental] Azure File Share name within the storage account.
-      Supports up to 100 TiB per share.'
+      Used by azure-files and azure-files-nfs storage types. Supports up to 100 TiB per share.'
+  azureBlobContainer:
+    required: false
+    default: 'unity-builds'
+    description:
+      '[Orchestrator] [Experimental] Azure Blob container name for blob-copy storage type.'
   azureSubscriptionId:
     required: false
     default: ''