fix: frontend-backend integration — 14 issues resolved

- nginx: add proxy routes for /settings/, /templates/, /ipam/, /logs/, /admin/, /health
- dashboard: fix data format mismatch (servers[] not nodes[]/vms[])
- dashboard: add WebSocket subscription to dashboard_metrics for real-time updates
- dashboard: connect activity feed to /logs/api/logs endpoint
- dashboard: reduce polling to 15s with WS as primary update source
- graphs: fix rrddata response unwrap (backend returns {data:[],timeframe:''})
- graphs: add i18n translations for chart titles
- console: add xterm.js CSS import for proper terminal rendering
- console: add i18n translations (connecting, reconnect)
- workspace: add switcher dropdown in TopBar
- workspace: add edit dialog in WorkspacesPage
- workspace: create Zustand store with localStorage persistence
- workspace: add X-Active-Workspace header to API client
- sidebar: replace generic icon with actual favicon.svg logo
- instances: translate RowActionMenu and InstanceDetailPage strings
- locales: add graphs, console, workspace, instance tab keys to en/ru

backend/app/api/proxmox/snapshots.py

@@ -1,6 +1,5 @@
 from fastapi import APIRouter, Depends, Request, HTTPException, Query, Form, status, WebSocket, WebSocketDisconnect
-from fastapi.responses import HTMLResponse, JSONResponse
-from fastapi.templating import Jinja2Templates
+from fastapi.responses import JSONResponse
 from sqlalchemy.orm import Session
 from sqlalchemy import func
 from loguru import logger
@@ -16,12 +15,10 @@ from ...schemas import ProxmoxServerCreate, ProxmoxServerUpdate, ProxmoxServerRe
 from ...proxmox_client import ProxmoxClient, get_proxmox_resources
 from ...auth import get_current_user, PermissionChecker, require_permission, check_permission
 from ...logging_service import LoggingService
-from ...template_helpers import add_i18n_context
 from ...ipam_service import IPAMService
 from ._helpers import (check_vm_access, require_vm_access, _get_proxmox_client,
                         get_next_vmid, archive_and_delete_snapshots,
-                        save_vm_instance, get_vm_instance, soft_delete_vm_instance,
-                        templates)
+                        save_vm_instance, get_vm_instance, soft_delete_vm_instance)
 
 router = APIRouter()