feat(frontend): 添加 Zustand store 架构

- 创建 5 个领域 store：runtimeStore, marketStore, portfolioStore, agentStore, uiStore
- 更新 CLAUDE.md 记录架构改进
- Zustand 已安装但 stores 尚未在 App.jsx 中使用（渐进迁移）

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/store/uiStore.js

@@ -0,0 +1,40 @@
+import { create } from 'zustand';
+
+/**
+ * UI Store - UI state, view management, layout
+ */
+export const useUIStore = create((set) => ({
+  // Current view
+  currentView: 'traders', // 'traders' | 'room' | 'explain' | 'chart' | 'statistics' | 'runtime'
+  setCurrentView: (currentView) => set({ currentView }),
+
+  // Chart tab
+  chartTab: 'all',
+  setChartTab: (chartTab) => set({ chartTab }),
+
+  // Initial animation
+  isInitialAnimating: true,
+  setIsInitialAnimating: (isInitialAnimating) => set({ isInitialAnimating }),
+
+  // Last update timestamp
+  lastUpdate: new Date(),
+  setLastUpdate: (lastUpdate) => set({ lastUpdate }),
+
+  // Is updating
+  isUpdating: false,
+  setIsUpdating: (isUpdating) => set({ isUpdating }),
+
+  // Room bubbles
+  bubbles: {},
+  setBubbles: (bubbles) => set({ bubbles }),
+
+  // Resizable panels
+  leftWidth: 70,
+  setLeftWidth: (leftWidth) => set({ leftWidth }),
+  isResizing: false,
+  setIsResizing: (isResizing) => set({ isResizing }),
+
+  // Now timestamp (for current time display)
+  now: new Date(),
+  setNow: (now) => set({ now }),
+}));