Parse KVM domain metadata by local name: libvirt returns it without a namespace

Run 3 on the real host got past Create and failed in Get: libvirt 11.6
selects the <instance> element by our URI in DomainGetMetadata but hands
it back with no namespace declaration, and the parser required the URI
on the element. The lookup already guarantees the namespace, so match on
the local name only. The fake now strips the declaration the way libvirt
does, and a new test pins the bare form. Execution log updated.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

internal/provider/kvm/fake_test.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"slices"
+	"strings"
 	"sync"
 
 	libvirt "github.com/digitalocean/go-libvirt"
@@ -151,8 +152,11 @@ func (f *fakeAPI) DomainDefineXML(raw string) (libvirt.Domain, error) {
 	if err != nil {
 		return libvirt.Domain{}, lvError(libvirt.ErrXMLError, "%v", err)
 	}
+	// libvirt hands the element back without its namespace declaration
+	// (seen on 11.6); mimic that so Get/ListByTag parse the real shape.
+	stored := strings.Replace(string(meta), ` xmlns="`+metadataURI+`"`, "", 1)
 	existing := f.domains[d.Name]
-	nd := &fakeDomain{name: d.Name, xml: raw, metadata: string(meta)}
+	nd := &fakeDomain{name: d.Name, xml: raw, metadata: stored}
 	if existing != nil {
 		nd.running = existing.running
 		nd.addrs = existing.addrs