feat(client): 桌面端日志加本地时间戳前缀 [HH:MM:SS.mmm]

新增 log_time.dart(共享 logTime() helper),DesktopKernel / DesktopVpnBridge
所有日志行首打 [时:分:秒.毫秒],便于排查连接时序。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/lib/bridge/desktop_vpn_bridge.dart

@@ -25,6 +25,7 @@ import 'dart:convert';
 import 'dart:io';
 
 import 'kernel_process.dart';
+import 'log_time.dart';
 import 'vpn_bridge.dart';
 
 /// 桌面端 VPN 桥接实现（macOS / Linux / Windows PoC）。
@@ -100,9 +101,9 @@ class DesktopVpnBridge implements VpnBridge {
 
     // 3. 写 config 到应用支持目录（0600 权限）
     final configPath = await writeConfig(enrichedJson);
-    print('[DesktopVpnBridge] config written: $configPath');
-    print('[DesktopVpnBridge] clash_api port=$port secret_len=${secret.length}');
-    print('[DesktopVpnBridge] killSwitch=$_killSwitchEnabled');
+    print('${logTime()}[DesktopVpnBridge] config written: $configPath');
+    print('${logTime()}[DesktopVpnBridge] clash_api port=$port secret_len=${secret.length}');
+    print('${logTime()}[DesktopVpnBridge] killSwitch=$_killSwitchEnabled');
 
     // 4. 启动内核子进程（blocking until Clash API ready or error）
     await _kernel.spawn(configPath);
@@ -141,7 +142,7 @@ class DesktopVpnBridge implements VpnBridge {
     try {
       await _kernel.clashApiClient.selectProxy('proxy', tag);
     } catch (e) {
-      print('[DesktopVpnBridge] selectOutbound(tag=$tag) error: $e');
+      print('${logTime()}[DesktopVpnBridge] selectOutbound(tag=$tag) error: $e');
       rethrow;
     }
   }
@@ -177,11 +178,11 @@ class DesktopVpnBridge implements VpnBridge {
   Future<void> setKillSwitch({required bool on}) async {
     if (_killSwitchEnabled == on) return;
     _killSwitchEnabled = on;
-    print('[DesktopVpnBridge] setKillSwitch=$on');
+    print('${logTime()}[DesktopVpnBridge] setKillSwitch=$on');
 
     // 若内核正在运行，用新设置重载（会有约 1~2s 重连）
     if (_kernel.isRunning && _lastUserConfigJson != null) {
-      print('[DesktopVpnBridge] reloading kernel for killSwitch change');
+      print('${logTime()}[DesktopVpnBridge] reloading kernel for killSwitch change');
       // 暂停自动重连，避免 kill 触发重连定时器
       final wasAutoReconnect = _shouldAutoReconnect;
       _shouldAutoReconnect = false;
@@ -230,17 +231,17 @@ class DesktopVpnBridge implements VpnBridge {
     _reconnectAttempt++;
 
     print(
-        '[DesktopVpnBridge] auto-reconnect in ${delaySec}s (attempt $_reconnectAttempt)');
+        '${logTime()}[DesktopVpnBridge] auto-reconnect in ${delaySec}s (attempt $_reconnectAttempt)');
 
     _reconnectTimer = Timer(Duration(seconds: delaySec), () async {
       if (!_shouldAutoReconnect || _lastUserConfigJson == null) return;
       try {
-        print('[DesktopVpnBridge] auto-reconnect: attempting start...');
+        print('${logTime()}[DesktopVpnBridge] auto-reconnect: attempting start...');
         await start(_lastUserConfigJson!);
         _reconnectAttempt = 0; // 成功后重置退避计数
-        print('[DesktopVpnBridge] auto-reconnect: success');
+        print('${logTime()}[DesktopVpnBridge] auto-reconnect: success');
       } catch (e) {
-        print('[DesktopVpnBridge] auto-reconnect: start failed: $e');
+        print('${logTime()}[DesktopVpnBridge] auto-reconnect: start failed: $e');
         // start() 失败（内核未能启动）→ 手动调度下一次重试
         if (_shouldAutoReconnect) _scheduleReconnect();
       }
@@ -341,7 +342,7 @@ class DesktopVpnBridge implements VpnBridge {
       try {
         await Process.run('chmod', ['600', file.path]);
       } catch (_) {
-        print('[DesktopVpnBridge] warning: chmod 600 failed for ${file.path}');
+        print('${logTime()}[DesktopVpnBridge] warning: chmod 600 failed for ${file.path}');
       }
     }
     return file.path;

client/lib/bridge/kernel_process.dart

@@ -30,6 +30,7 @@ import 'dart:math' as math;
 
 import 'package:http/http.dart' as http;
 
+import 'log_time.dart';
 import 'vpn_bridge.dart';
 
 // ══════════════════════════════════════════════════════════════════
@@ -481,7 +482,7 @@ class DesktopKernelProcess implements KernelProcess {
   }
 
   void _log(String msg) {
-    print('[DesktopKernel] $msg');
+    print('${logTime()}[DesktopKernel] $msg');
     if (!_logCtrl.isClosed) _logCtrl.add(msg);
   }
 

client/lib/bridge/log_time.dart

@@ -0,0 +1,8 @@
+// log_time.dart — 桌面端日志统一时间戳前缀。
+// 返回本地时间 "[HH:MM:SS.mmm] ",拼在日志行首便于排查时序。
+
+String logTime() {
+  final n = DateTime.now();
+  String p(int v, [int w = 2]) => v.toString().padLeft(w, '0');
+  return '[${p(n.hour)}:${p(n.minute)}:${p(n.second)}.${p(n.millisecond, 3)}] ';
+}