Create Azure adapter: ElasticSanVolume (#4535)

<!-- CURSOR_AGENT_PR_BODY_BEGIN -->
## Summary

This PR adds a new Azure adapter for Elastic SAN Volumes
(`ElasticSanVolume`), following the azure-adapter-creation skill
workflow.

## Changes

### Client Interface
- `sources/azure/clients/elastic-san-volume-client.go`: Client interface
wrapping Azure SDK's `VolumesClient`
- `sources/azure/shared/mocks/mock_elastic_san_volume_client.go`:
Generated mock for testing

### Adapter Implementation
- `sources/azure/manual/elastic-san-volume.go`: SearchableWrapper
implementation for ElasticSanVolume
- `Get`: Retrieves a single volume by elasticSanName, volumeGroupName,
volumeName
  - `Search`: Lists all volumes under a volume group
  - `SearchStream`: Streaming variant of Search
- Linked item queries to parent ElasticSan, VolumeGroup, source
snapshot/volume, ManagedBy VM, and DNS hostname

### Registration
- `sources/azure/manual/adapters.go`: Added client creation and adapter
registration

### Tests
- `sources/azure/manual/elastic-san-volume_test.go`: Unit tests with
mocks
- `sources/azure/integration-tests/elastic-san-volume_test.go`:
Integration tests against real Azure APIs

## Linked Item Queries

The adapter creates linked item queries for:
- **Parent ElasticSan** (GET)
- **Parent ElasticSanVolumeGroup** (GET with composite key)
- **Source ElasticSanVolumeSnapshot** (GET when created from snapshot)
- **Source ElasticSanVolume** (GET when cloned from volume)
- **ManagedBy ComputeVirtualMachine** (GET when managed by VM)
- **StorageTarget DNS hostname** (SEARCH via NetworkDNS)

## Self-Review Checklist

- [x] **IAMPermissions**: Present, references
`Microsoft.ElasticSan/elasticSans/volumegroups/volumes/read`
- [x] **PredefinedRole**: Present, uses `Reader`
- [x] **LinkedItemQueries**: 6 link types verified (ElasticSan,
VolumeGroup, VolumeSnapshot, Volume, VM, DNS). DNS link for
StorageTarget hostname included.
- [x] **PotentialLinks**: 6 types listed (ElasticSan,
ElasticSanVolumeGroup, ElasticSanVolumeSnapshot, ElasticSanVolume,
ComputeVirtualMachine, NetworkDNS), matches LinkedItemQueries
- [x] **Unit tests**: All passing (Get, GetWithLinks,
GetWithInsufficientQueryParts, GetWithEmpty*, ErrorHandling, Search,
SearchWithEmpty*, SearchStream, StaticTests)
- [x] **Integration test**: All sub-tests passing (Setup, Run/GetVolume,
Run/SearchVolumes, Run/VerifyLinkedItems, Run/VerifyItemAttributes,
Teardown) against live Azure APIs

All checklist items passed. Ready for review.

## Related

- Linear Issue: ENG-3546
- Parent Adapter: `elastic-san-volume-group.go` (already has SEARCH link
to ElasticSanVolume)
<!-- CURSOR_AGENT_PR_BODY_END -->

Linear Issue:
[ENG-3546](https://linear.app/overmind/issue/ENG-3546/create-azure-adapter-elasticsanvolume)

<div><a
href="https://cursor.com/agents/bc-2a755c21-1fe0-4be9-b498-c4f3f7520652"><picture><source
media="(prefers-color-scheme: dark)"
srcset="https://cursor.com/assets/images/open-in-web-dark.png"><source
media="(prefers-color-scheme: light)"
srcset="https://cursor.com/assets/images/open-in-web-light.png"><img
alt="Open in Web" width="114" height="28"
src="https://cursor.com/assets/images/open-in-web-dark.png"></picture></a>&nbsp;<a
href="https://cursor.com/background-agent?bcId=bc-2a755c21-1fe0-4be9-b498-c4f3f7520652"><picture><source
media="(prefers-color-scheme: dark)"
srcset="https://cursor.com/assets/images/open-in-cursor-dark.png"><source
media="(prefers-color-scheme: light)"
srcset="https://cursor.com/assets/images/open-in-cursor-light.png"><img
alt="Open in Cursor" width="131" height="28"
src="https://cursor.com/assets/images/open-in-cursor-dark.png"></picture></a>&nbsp;</div>

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: Lionel Wilson <Lionel-Wilson@users.noreply.github.com>
GitOrigin-RevId: 2708a089bc7b13fbe57e03128564d18e60201374

Author: 2 people

sources/azure/clients/elastic-san-volume-client.go

@@ -0,0 +1,35 @@
+package clients
+
+import (
+	"context"
+
+	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/elasticsan/armelasticsan"
+)
+
+//go:generate mockgen -destination=../shared/mocks/mock_elastic_san_volume_client.go -package=mocks -source=elastic-san-volume-client.go
+
+// ElasticSanVolumePager is a type alias for the generic Pager interface with volume list response type.
+type ElasticSanVolumePager = Pager[armelasticsan.VolumesClientListByVolumeGroupResponse]
+
+// ElasticSanVolumeClient is an interface for interacting with Azure Elastic SAN volumes.
+type ElasticSanVolumeClient interface {
+	Get(ctx context.Context, resourceGroupName string, elasticSanName string, volumeGroupName string, volumeName string, options *armelasticsan.VolumesClientGetOptions) (armelasticsan.VolumesClientGetResponse, error)
+	NewListByVolumeGroupPager(resourceGroupName string, elasticSanName string, volumeGroupName string, options *armelasticsan.VolumesClientListByVolumeGroupOptions) ElasticSanVolumePager
+}
+
+type elasticSanVolumeClient struct {
+	client *armelasticsan.VolumesClient
+}
+
+func (c *elasticSanVolumeClient) Get(ctx context.Context, resourceGroupName string, elasticSanName string, volumeGroupName string, volumeName string, options *armelasticsan.VolumesClientGetOptions) (armelasticsan.VolumesClientGetResponse, error) {
+	return c.client.Get(ctx, resourceGroupName, elasticSanName, volumeGroupName, volumeName, options)
+}
+
+func (c *elasticSanVolumeClient) NewListByVolumeGroupPager(resourceGroupName string, elasticSanName string, volumeGroupName string, options *armelasticsan.VolumesClientListByVolumeGroupOptions) ElasticSanVolumePager {
+	return c.client.NewListByVolumeGroupPager(resourceGroupName, elasticSanName, volumeGroupName, options)
+}
+
+// NewElasticSanVolumeClient creates a new ElasticSanVolumeClient from the Azure SDK client.
+func NewElasticSanVolumeClient(client *armelasticsan.VolumesClient) ElasticSanVolumeClient {
+	return &elasticSanVolumeClient{client: client}
+}