proxmox: review fixes, real-host validation record, changelog

Phase 10. Two review passes (go-operator-reviewer, /code-review high)
over the branch, recorded in docs/reviews/2026-09-23-proxmox-provider-review/:
9 findings fixed, 3 accepted as documented limits, 7 rejected with a
reason.

- Delete removes the seed between the stop and the destroy, so a failed
  seed delete leaves the VM for the next Delete instead of leaking the
  ISO; a Permanent refusal on the every-node path fails the call.
- Create skips a probe VMID whose listed name is someone else's without
  waiting on its lock.
- The three answers Phase 0 never captured are fixtures now: a missing
  storage is a 400 (the Checker reports StorageNotFound), a hibernated
  VM is destroyable (Delete destroys ours), a paused VM stops.
- TestProxmox_lifecycle and TestProxmoxCheck_realHost passed on pv1-1
  (PVE 9.2.20); the docs record the run and drop "not yet run".

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

internal/provider/proxmox/provider_test.go

@@ -310,13 +310,6 @@ func TestProvider_everyErrorIsWrappedWithConfiguredName(t *testing.T) {
 			op:   "delete", id: "vms/150042", class: provider.ErrPermanent,
 		},
 		{name: "delete waiting on the name lock", setup: holdNameLock, call: del, op: "delete", id: "self", class: provider.ErrTransient},
-		{
-			name: "delete hibernated vm",
-			setup: func(fx *fixture, _ context.CancelFunc) {
-				fx.addOurVM(testVMID, testName, "stopped").lock = lockSuspended
-			},
-			call: del, op: "delete", id: "self", class: provider.ErrPermanent,
-		},
 		{
 			name: "delete destroy task fails",
 			setup: func(fx *fixture, _ context.CancelFunc) {
@@ -579,7 +572,7 @@ func TestLogging_noOpLinesAtV1(t *testing.T) {
 			name: "seed delete skipped on each node",
 			setup: func(fx *fixture) {
 				fx.p.cfg.Nodes = []string{fakeNode, "pv1-2"}
-				fx.fake.failWith("DeleteVolume", loadAPIError(fx.t, "err_forbidden_volume_delete"))
+				fx.fake.failWith("DeleteVolume", fakeErr(500, "fake: storage 'proxy-seeds' is not available on this node"))
 			},
 			call: del, msg: "proxmox seed delete failed on a node, skipped", want: 2,
 		},