fix: 流量统计窗口四个问题

1. 窗口宽度 560->620 容纳列宽，关闭按钮不再被遮挡
2. tab 切换无效：onCurrentTabChanged 已生效，补充窗口可见时立即刷新
3. 数值不刷新：新增 5 秒定时器（窗口可见时运行），不依赖 C++ 30 秒信号
4. 国际化：补全 TrafficStatistics/ByDay/ByMonth 等 12 条翻译

package/components/TrafficStatsWindow.qml

@@ -94,7 +94,7 @@ Window {
         root.totals = { rx: tRx, tx: tTx, total: tRx + tTx }
     }
 
-    width: 560
+    width: 620
     height: 440
     visible: false
     flags: Qt.FramelessWindowHint | Qt.Window
@@ -113,6 +113,18 @@ Window {
     // 切换 tab 或首次创建时重建表格模型
     onCurrentTabChanged: buildStatsModel()
     Component.onCompleted: buildStatsModel()
+    // 窗口显示时立即刷新一次，确保数据最新
+    onVisibleChanged: if (visible) buildStatsModel()
+
+    // 定时刷新：窗口可见时每 5 秒重建表格，不依赖 C++ 30 秒信号
+    // 设计原因：C++ 降频 30 秒通知，用户打开窗口期间看不到实时更新；
+    // 窗口可见时主动 5 秒刷新，关闭时停止，兼顾实时性与性能
+    Timer {
+        interval: 5000
+        repeat: true
+        running: root.visible
+        onTriggered: buildStatsModel()
+    }
 
     // 窗口主体：圆角卡片（背景与边框随 isDarkMode 切换深浅），1px 边框模拟 DTK 窗口描边
     Rectangle {

translations/jnetapplet_zh_CN.ts

@@ -270,5 +270,68 @@
         <source>About</source>
         <translation>关于</translation>
     </message>
+    <message>
+        <location filename="../package/networkview.qml" line="314"/>
+        <source>Traffic Statistics</source>
+        <translation>流量统计</translation>
+    </message>
+</context>
+<context>
+    <name>TrafficStatsWindow</name>
+    <message>
+        <location filename="../package/components/TrafficStatsWindow.qml" line="132"/>
+        <source>Traffic Statistics</source>
+        <translation>流量统计</translation>
+    </message>
+    <message>
+        <location filename="../package/components/TrafficStatsWindow.qml" line="158"/>
+        <source>By Day</source>
+        <translation>按日</translation>
+    </message>
+    <message>
+        <location filename="../package/components/TrafficStatsWindow.qml" line="184"/>
+        <source>By Month</source>
+        <translation>按月</translation>
+    </message>
+    <message>
+        <location filename="../package/components/TrafficStatsWindow.qml" line="202"/>
+        <source>Accumulated by interface</source>
+        <translation>按接口累计</translation>
+    </message>
+    <message>
+        <location filename="../package/components/TrafficStatsWindow.qml" line="218"/>
+        <source>Date</source>
+        <translation>日期</translation>
+    </message>
+    <message>
+        <location filename="../package/components/TrafficStatsWindow.qml" line="218"/>
+        <source>Month</source>
+        <translation>月份</translation>
+    </message>
+    <message>
+        <location filename="../package/components/TrafficStatsWindow.qml" line="225"/>
+        <source>Interface</source>
+        <translation>接口</translation>
+    </message>
+    <message>
+        <location filename="../package/components/TrafficStatsWindow.qml" line="232"/>
+        <source>Download</source>
+        <translation>下载</translation>
+    </message>
+    <message>
+        <location filename="../package/components/TrafficStatsWindow.qml" line="239"/>
+        <source>Upload</source>
+        <translation>上传</translation>
+    </message>
+    <message>
+        <location filename="../package/components/TrafficStatsWindow.qml" line="246"/>
+        <source>Total</source>
+        <translation>总计</translation>
+    </message>
+    <message>
+        <location filename="../package/components/TrafficStatsWindow.qml" line="283"/>
+        <source>No traffic records yet</source>
+        <translation>暂无流量记录</translation>
+    </message>
 </context>
 </TS>