Eng 3140 phase 1 single adapter integration test pr (#4281)

<!-- CURSOR_SUMMARY -->
> [!NOTE]
> **Medium Risk**
> Adds a new Azure discovery adapter and wires it into global adapter
registration, which can affect runtime discovery behavior and
linked-item traversal. Also introduces a new Azure integration test that
provisions real resources, increasing CI/config sensitivity if enabled.
>
> **Overview**
> Adds support for Azure Private DNS Zone Virtual Network Links via a
new `NetworkDNSVirtualNetworkLink` SearchableWrapper, including
linked-item queries to the parent private DNS zone and the referenced
virtual network (with cross-resource-group scope extraction).
>
> Registers the new adapter in `manual/adapters.go`, adds a thin
`VirtualNetworkLinksClient` interface + generated mock, and updates
`shared/utils.go` resource-ID path key mapping for this new type.
>
> Adds both unit tests and a full Azure integration test that provisions
a VNet, private DNS zone, and virtual network link, then validates
`Get`/`Search`, item attributes, and linked-item queries. Updates the
adapter-creation skill docs to require bidirectional parent/child SEARCH
links and to include integration test guidance.
>
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
b25ff898296056b50fc9562b4f7e7838b27fe2e8. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

GitOrigin-RevId: 8865f06c70fba163edfa433bc7a66c8baa166ddb

Author: DavidS-ovm

sources/azure/clients/virtual-network-links-client.go

@@ -0,0 +1,32 @@
+package clients
+
+import (
+	"context"
+
+	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/privatedns/armprivatedns"
+)
+
+//go:generate mockgen -destination=../shared/mocks/mock_virtual_network_links_client.go -package=mocks -source=virtual-network-links-client.go
+
+type VirtualNetworkLinksPager = Pager[armprivatedns.VirtualNetworkLinksClientListResponse]
+
+type VirtualNetworkLinksClient interface {
+	NewListPager(resourceGroupName string, privateZoneName string, options *armprivatedns.VirtualNetworkLinksClientListOptions) VirtualNetworkLinksPager
+	Get(ctx context.Context, resourceGroupName string, privateZoneName string, virtualNetworkLinkName string, options *armprivatedns.VirtualNetworkLinksClientGetOptions) (armprivatedns.VirtualNetworkLinksClientGetResponse, error)
+}
+
+type virtualNetworkLinksClient struct {
+	client *armprivatedns.VirtualNetworkLinksClient
+}
+
+func (c *virtualNetworkLinksClient) NewListPager(resourceGroupName string, privateZoneName string, options *armprivatedns.VirtualNetworkLinksClientListOptions) VirtualNetworkLinksPager {
+	return c.client.NewListPager(resourceGroupName, privateZoneName, options)
+}
+
+func (c *virtualNetworkLinksClient) Get(ctx context.Context, resourceGroupName string, privateZoneName string, virtualNetworkLinkName string, options *armprivatedns.VirtualNetworkLinksClientGetOptions) (armprivatedns.VirtualNetworkLinksClientGetResponse, error) {
+	return c.client.Get(ctx, resourceGroupName, privateZoneName, virtualNetworkLinkName, options)
+}
+
+func NewVirtualNetworkLinksClient(client *armprivatedns.VirtualNetworkLinksClient) VirtualNetworkLinksClient {
+	return &virtualNetworkLinksClient{client: client}
+}