feat: v1.1.0 — backup module, IPAM node binding, HA, task queue, theme CSS

- Backup module: full CRUD for storages, backup files, scheduled jobs (APScheduler)
- Proxmox client: storage/backup/restore/HA methods
- IPAM: proxmox_node field, server+node binding for networks and allocations
- Task queue service: improvements and new task types
- Monitoring worker: extended metrics and alerts
- HA support: add/remove VMs from Proxmox HA groups
- tasks.html: new task tracking page
- proxmox_vms.html: major UI update (bulk ops, HA, snapshots)
- backups.html: full backup management UI (3 tabs)
- base.html: sidebar backup link, websocket manager
- theme.css: full CSS variables theme, 395 lines added
- migrations: migration #15 (BackupJob), #16 (proxmox_node)
- RBAC: backup resource permissions
- websocket_manager.py: new module for WS connections

backend/app/api/proxmox/__init__.py

@@ -5,6 +5,7 @@ from .snapshots import router as snapshots_router
 from .vms import router as vms_router
 from .tasks import router as tasks_router
 from .backup import router as backup_router
+from .cluster import router as cluster_router
 from ._helpers import get_next_vmid, save_vm_instance, get_vm_instance
 
 router = APIRouter()
@@ -14,3 +15,4 @@ router.include_router(snapshots_router)
 router.include_router(vms_router)
 router.include_router(tasks_router)
 router.include_router(backup_router)
+router.include_router(cluster_router)