feat(vm-ops): make reinstall/clone/change-password async via DeployTask

Backend:
- Add DeployTask.kind column ('deploy'|'reinstall'|'clone'|'change_password')
  + Migration 23: ALTER TABLE deploy_tasks ADD kind, drop NOT NULL on template_id
- Update DeployTask.to_dict() with kind-aware Russian descriptions
- New backend/app/api/proxmox/async_ops.py with three workers:
    _do_reinstall_sync, _do_clone_sync, _do_change_password_sync
  All run on shared _deploy_executor thread pool from templates.py and
  report progress through _update_deploy_task (DB + WebSocket broadcast)
- Rewrite five vms.py endpoints to return 202 + DeployTaskStartResponse:
    POST /vm/{vmid}/clone, /container/{vmid}/clone,
    POST /vm/{vmid}/reinstall,
    POST /vm/{vmid}/change-password, /container/{vmid}/change-password

Frontend:
- DeployTask: add 'kind' and 'server_id' fields
- useCloneInstance/useReinstallInstance/useChangePassword now return
  AsyncTaskResponse {task_id, status, name}; remove invalidateQueries
- InstanceActionDialogs: each onSuccess pushes task to deploy-tasks-store
  with appropriate kind, shows 'launched in background' toast
- InstancesPage:
  * ghostRows only for kind in {deploy, clone}, deduped by (server_id, vmid)
  * reinstall / change_password tasks shown as inline overlay (badge + ring)
    on the existing VM row's status column

frontend/src/hooks/use-instances.ts

@@ -298,36 +298,31 @@ interface CloneRequest {
   description?: string;
 }
 
+export interface AsyncTaskResponse {
+  task_id: number;
+  status: string;
+  name: string;
+}
+
 export function useCloneInstance(serverId: number, vmid: number, type: string, node: string) {
-  const qc = useQueryClient();
   const prefix = type === 'lxc' ? 'container' : 'vm';
-  return useMutation<{ status: string; new_vmid: number; upid: string }, Error, CloneRequest>({
+  return useMutation<AsyncTaskResponse, Error, CloneRequest>({
     mutationFn: (body) =>
       apiClient.post(`/proxmox/api/${serverId}/${prefix}/${vmid}/clone?node=${node}`, body),
-    onSuccess: () => {
-      qc.invalidateQueries({ queryKey: vmKeys.all });
-      qc.invalidateQueries({ queryKey: vmKeys.resourcesAll });
-    },
   });
 }
 
 export function useReinstallInstance(serverId: number, vmid: number, node: string) {
-  const qc = useQueryClient();
-  return useMutation<{ status: string; vmid: number; upid: string }, Error, void>({
+  return useMutation<AsyncTaskResponse, Error, void>({
     mutationFn: () =>
       apiClient.post(`/proxmox/api/${serverId}/vm/${vmid}/reinstall?node=${node}`),
-    onSuccess: () => {
-      qc.invalidateQueries({ queryKey: vmKeys.all });
-      qc.invalidateQueries({ queryKey: vmKeys.config(serverId, vmid) });
-      qc.invalidateQueries({ queryKey: vmKeys.status(serverId, vmid) });
-    },
   });
 }
 
 // ==================== Change Password ====================
 export function useChangePassword(serverId: number, vmid: number, type: string, node: string) {
   const prefix = type === 'lxc' ? 'container' : 'vm';
-  return useMutation<{ status: string }, Error, { username: string; password: string }>({
+  return useMutation<AsyncTaskResponse, Error, { username: string; password: string }>({
     mutationFn: (body) =>
       apiClient.post(`/proxmox/api/${serverId}/${prefix}/${vmid}/change-password?node=${node}`, body),
   });