controller v0.48.0: slice 10 P2C — enroll passes the drive into the guest

agentapi GuestAttach(where) → POST /disks/guest-attach; runStorageInit/Attach +
handleStorageRegister call attachIntoGuest after register (best-effort, P3 heals).
Closes Branch A: enrolled drives become usable in the guest, banner clears.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

controller/internal/web/storage_handlers_test.go

@@ -32,6 +32,7 @@ type mockAgent struct {
 	assignCalls  []assignCall
 	disksCalls   int
 	formatCalls  []formatCall
+	guestAttachCalls []string
 }
 
 type assignCall struct{ uuid, where, fstype string }
@@ -55,6 +56,10 @@ func (m *mockAgent) AssignDisk(_ context.Context, uuid, where, fstype, _ string)
 func (m *mockAgent) EjectDisk(_ context.Context, where string) (agentapi.EjectResult, error) {
 	return agentapi.EjectResult{Ejected: where}, nil
 }
+func (m *mockAgent) GuestAttach(_ context.Context, where string) error {
+	m.guestAttachCalls = append(m.guestAttachCalls, where)
+	return nil
+}
 
 func testServer(t *testing.T) *Server {
 	t.Helper()
@@ -166,6 +171,10 @@ func TestRunStorageInit_Success(t *testing.T) {
 	if len(paths) != 1 || paths[0].Path != "/mnt/hdd1" || paths[0].Label != "Külső HDD" || !paths[0].IsDefault || !paths[0].Schedulable {
 		t.Fatalf("StoragePath not registered as expected: %+v", paths)
 	}
+	// P2C: enroll must pass the drive into the guest.
+	if len(agent.guestAttachCalls) != 1 || agent.guestAttachCalls[0] != "/mnt/hdd1" {
+		t.Fatalf("enroll did not guest-attach the drive: %+v", agent.guestAttachCalls)
+	}
 }
 
 // Attach is non-destructive: resolve UUID → assign → register (no format).