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

frontend/.gitignore

@@ -0,0 +1,24 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules
+dist
+dist-ssr
+*.local
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?