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/index.html

@@ -0,0 +1,16 @@
+<!doctype html>
+<html lang="en" class="dark">
+  <head>
+    <meta charset="UTF-8" />
+    <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <link rel="preconnect" href="https://fonts.googleapis.com" />
+    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
+    <link href="https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,100..1000;1,9..40,100..1000&family=JetBrains+Mono:wght@400;500&display=swap" rel="stylesheet" />
+    <title>PVEmanager</title>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.tsx"></script>
+  </body>
+</html>