feat(Center): 投资规划中心新建计划/复盘乐观更新

- planningSlice: 添加 optimisticAddEvent、replaceEvent、removeEvent reducers
- EventFormModal: 新建模式使用乐观更新，立即关闭弹窗显示数据
- account.js: Mock 数据按日期倒序排序，最新事件在前

乐观更新流程：
1. 创建临时事件（负数 ID）立即更新 UI
2. 后台发送 API 请求
3. 成功后替换为真实数据，失败则回滚

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/store/slices/planningSlice.ts

@@ -196,6 +196,25 @@ const planningSlice = createSlice({
       state.allEvents.push(action.payload);
       state.lastUpdated = Date.now();
     },
+    /** 乐观添加事件（插入到开头，使用临时 ID） */
+    optimisticAddEvent: (state, action: PayloadAction<InvestmentEvent>) => {
+      state.allEvents.unshift(action.payload); // 新事件插入开头
+      state.lastUpdated = Date.now();
+    },
+    /** 替换临时事件为真实事件 */
+    replaceEvent: (state, action: PayloadAction<{ tempId: number; realEvent: InvestmentEvent }>) => {
+      const { tempId, realEvent } = action.payload;
+      const index = state.allEvents.findIndex(e => e.id === tempId);
+      if (index !== -1) {
+        state.allEvents[index] = realEvent;
+      }
+      state.lastUpdated = Date.now();
+    },
+    /** 移除事件（用于回滚） */
+    removeEvent: (state, action: PayloadAction<number>) => {
+      state.allEvents = state.allEvents.filter(e => e.id !== action.payload);
+      state.lastUpdated = Date.now();
+    },
   },
   extraReducers: (builder) => {
     builder
@@ -251,7 +270,14 @@ const planningSlice = createSlice({
 
 // ==================== 导出 ====================
 
-export const { clearEvents, setEvents, addEvent } = planningSlice.actions;
+export const {
+  clearEvents,
+  setEvents,
+  addEvent,
+  optimisticAddEvent,
+  replaceEvent,
+  removeEvent,
+} = planningSlice.actions;
 
 export default planningSlice.reducer;