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>

src/stores/useDisabledModelsStore.ts

@@ -0,0 +1,50 @@
+/**
+ * 禁用模型状态管理
+ * 全局管理已禁用的模型，确保所有组件状态同步
+ */
+
+import { create } from 'zustand';
+
+interface DisabledModelsState {
+  /** 已禁用的模型集合，格式：`${source}|||${model}` */
+  disabledModels: Set<string>;
+  /** 添加禁用模型 */
+  addDisabledModel: (source: string, model: string) => void;
+  /** 移除禁用模型（恢复） */
+  removeDisabledModel: (source: string, model: string) => void;
+  /** 检查模型是否已禁用 */
+  isDisabled: (source: string, model: string) => boolean;
+  /** 清空所有禁用状态 */
+  clearAll: () => void;
+}
+
+export const useDisabledModelsStore = create<DisabledModelsState>()((set, get) => ({
+  disabledModels: new Set<string>(),
+
+  addDisabledModel: (source, model) => {
+    const key = `${source}|||${model}`;
+    set((state) => {
+      const newSet = new Set(state.disabledModels);
+      newSet.add(key);
+      return { disabledModels: newSet };
+    });
+  },
+
+  removeDisabledModel: (source, model) => {
+    const key = `${source}|||${model}`;
+    set((state) => {
+      const newSet = new Set(state.disabledModels);
+      newSet.delete(key);
+      return { disabledModels: newSet };
+    });
+  },
+
+  isDisabled: (source, model) => {
+    const key = `${source}|||${model}`;
+    return get().disabledModels.has(key);
+  },
+
+  clearAll: () => {
+    set({ disabledModels: new Set() });
+  },
+}));