fix: 修复货币符号显示问题

1. 新增 utils/currency.js 货币工具函数
2. 首页今日盈亏使用 todayProfitCurrency 动态获取货币符号
3. 详情页今日盈亏使用 todayProfitCurrency 而非 currency

pages/detail/detail.vue

@@ -50,7 +50,7 @@
           <view class="stat-item align-right">
             <text class="stat-label">当日盈亏</text>
             <text class="stat-val" :class="(portfolioData.todayProfit || 0) >= 0 ? 'text-red' : 'text-green'">
-              {{ (portfolioData.todayProfit || 0) >= 0 ? '+' : '' }}{{ getCurrencySymbol(portfolioData.currency) }}{{ (portfolioData.todayProfit || 0).toLocaleString('zh-CN', { minimumFractionDigits: 2, maximumFractionDigits: 2 }) }}
+              {{ (portfolioData.todayProfit || 0) >= 0 ? '+' : '' }}{{ getCurrencySymbol(portfolioData.todayProfitCurrency || portfolioData.currency) }}{{ (portfolioData.todayProfit || 0).toLocaleString('zh-CN', { minimumFractionDigits: 2, maximumFractionDigits: 2 }) }}
             </text>
           </view>
         </view>

pages/index/index.vue

@@ -41,7 +41,7 @@
         <view class="card-row bottom-row">
           <view class="stat-col">
             <text class="stat-label">今日账面变动</text>
-          <text class="stat-value">{{ (assetData.todayProfit || 0) >= 0 ? '+' : '' }}¥{{ (assetData.todayProfit || 0).toLocaleString('zh-CN', { minimumFractionDigits: 2, maximumFractionDigits: 2 }) }}</text>
+          <text class="stat-value">{{ (assetData.todayProfit || 0) >= 0 ? '+' : '' }}{{ getCurrencySymbol(assetData.todayProfitCurrency || 'CNY') }}{{ (assetData.todayProfit || 0).toLocaleString('zh-CN', { minimumFractionDigits: 2, maximumFractionDigits: 2 }) }}</text>
         </view>
         <view class="stat-col align-right">
           <text class="stat-label">历史总变动</text>
@@ -132,6 +132,7 @@
 import { ref } from 'vue';
 import { onShow } from '@dcloudio/uni-app';
 import { api } from '../../utils/api';
+import { getCurrencySymbol } from '../../utils/currency';
 
 // 加载状态
 const loading = ref(true);

utils/currency.js

@@ -0,0 +1,57 @@
+/**
+ * 货币工具函数
+ */
+
+/**
+ * 获取货币符号
+ * @param {string} currency - 货币代码 (CNY, USD, HKD 等)
+ * @returns {string} 货币符号
+ */
+export const getCurrencySymbol = (currency) => {
+  const symbols = {
+    'CNY': '¥',
+    'USD': '$',
+    'HKD': 'HK$',
+    'EUR': '€',
+    'GBP': '£',
+    'JPY': '¥',
+    'SGD': 'S$',
+    'AUD': 'A$'
+  };
+  return symbols[currency?.toUpperCase()] || '¥';
+};
+
+/**
+ * 格式化金额
+ * @param {number} amount - 金额
+ * @param {string} currency - 货币代码
+ * @param {number} decimals - 小数位数
+ * @returns {string} 格式化后的金额字符串
+ */
+export const formatAmount = (amount, currency = 'CNY', decimals = 2) => {
+  const symbol = getCurrencySymbol(currency);
+  const formatted = Math.abs(amount || 0).toLocaleString('zh-CN', {
+    minimumFractionDigits: decimals,
+    maximumFractionDigits: decimals
+  });
+  const sign = amount >= 0 ? '' : '-';
+  return `${sign}${symbol}${formatted}`;
+};
+
+/**
+ * 格式化金额（带正负号）
+ * @param {number} amount - 金额
+ * @param {string} currency - 货币代码
+ * @param {number} decimals - 小数位数
+ * @returns {string} 格式化后的金额字符串
+ */
+export const formatAmountWithSign = (amount, currency = 'CNY', decimals = 2) => {
+  const symbol = getCurrencySymbol(currency);
+  const formatted = Math.abs(amount || 0).toLocaleString('zh-CN', {
+    minimumFractionDigits: decimals,
+    maximumFractionDigits: decimals
+  });
+  if (amount > 0) return `+${symbol}${formatted}`;
+  if (amount < 0) return `-${symbol}${formatted}`;
+  return `${symbol}${formatted}`;
+};