feat: add monitor center module

Changes:
- Add monitor center page with KPI cards, charts and request logs
- Implement channel stats, failure analysis, model distribution visualization
- Support time range filtering (last 1/6/24 hours)
- Add model disable feature with related hooks and state management
- Optimize request logs list performance with virtual scrolling
- Improve mobile styles and table scrolling experience
- Add i18n support for Chinese and English

Modified files:
- src/pages/MonitorPage.tsx (added)
- src/components/monitor/* (added, 10 components)
- src/hooks/useDisableModel.ts (added)
- src/utils/monitor.ts (added)
- src/i18n/locales/*.json (modified)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitignore

@@ -30,3 +30,6 @@ settings.local.json
 *.njsproj
 *.sln
 *.sw?
+自定义 Web UI
+tmpclaude*
+.claude