feat: LXC container creation from CT templates

- Add LXC deploy API endpoints: GET /proxmox/api/lxc-templates/{id},
  GET /proxmox/api/lxc-storages/{id}, POST /proxmox/api/lxc/deploy
- Add ProxmoxClient.get_lxc_storage_templates() and get_node_storages()
- Fix duplicate create_lxc_container() — removed dead copy, updated
  canonical with nameserver/searchdomain params
- Fix wait_for_task(): accept WARNINGS:N exitstatus as success
- Add IPAM IP release on deploy failure
- Add frontend hooks: useLXCTemplates, useLXCStorages, useDeployLXC
  with 5-min staleTime caching
- Add LXC wizard steps to CreateInstanceWizard (type, template, config)
- Add LXC i18n keys to en.json and ru.json
- Add LXCTemplate and LXCDeployRequest TypeScript interfaces

backend/app/api/proxmox/__init__.py

@@ -7,6 +7,7 @@ from .tasks import router as tasks_router
 from .backup import router as backup_router
 from .cluster import router as cluster_router
 from .networks import router as networks_router
+from .lxc import router as lxc_router
 from ._helpers import get_next_vmid, save_vm_instance, get_vm_instance
 
 router = APIRouter()
@@ -18,3 +19,4 @@ router.include_router(tasks_router)
 router.include_router(backup_router)
 router.include_router(cluster_router)
 router.include_router(networks_router)
+router.include_router(lxc_router)