fix: Unable to obtain Windows server information (#963)

* fix: FormatException: Unexpected extension byte (at offset 8) error

* fix: PowerShell script error repair, Windows data parsing repair

* fix: Unable to obtain network card information

* fix: Unable to obtain system startup time

* fix conversation as resolved.

lib/data/helper/ssh_decoder.dart

@@ -0,0 +1,66 @@
+import 'dart:convert';
+
+import 'package:fl_lib/fl_lib.dart';
+import 'package:flutter_gbk2utf8/flutter_gbk2utf8.dart';
+
+/// Utility class for decoding SSH command output with encoding fallback
+class SSHDecoder {
+  /// Decodes bytes to string with multiple encoding fallback strategies
+  ///
+  /// Tries in order:
+  /// 1. UTF-8 (with allowMalformed for lenient parsing)
+  ///    - Windows PowerShell scripts now set UTF-8 output encoding by default
+  /// 2. GBK (for Windows Chinese systems)
+  ///    - In some cases, Windows will still revert to GBK.
+  ///    - Only attempted if UTF-8 produces replacement characters (<28>)
+  static String decode(
+    List<int> bytes, {
+    bool isWindows = false,
+    String? context,
+  }) {
+    if (bytes.isEmpty) return '';
+
+    // Try UTF-8 first with allowMalformed
+    try {
+      final result = utf8.decode(bytes, allowMalformed: true);
+      // Check if there are replacement characters indicating decode failure
+      // For non-Windows systems, always use UTF-8 result
+      if (!result.contains('<EFBFBD>') || !isWindows) {
+        return result;
+      }
+      // For Windows with replacement chars, log and try GBK fallback
+      if (isWindows && result.contains('<EFBFBD>')) {
+        final contextInfo = context != null ? ' [$context]' : '';
+        Loggers.app.info('UTF-8 decode has replacement chars$contextInfo, trying GBK fallback');
+      }
+    } catch (e) {
+      final contextInfo = context != null ? ' [$context]' : '';
+      Loggers.app.warning('UTF-8 decode failed$contextInfo: $e');
+    }
+
+    // For Windows or when UTF-8 has replacement chars, try GBK
+    try {
+      return gbk.decode(bytes);
+    } catch (e) {
+      final contextInfo = context != null ? ' [$context]' : '';
+      Loggers.app.warning('GBK decode failed$contextInfo: $e');
+      // Return empty string if all decoding attempts fail
+      return '';
+    }
+  }
+
+  /// Encodes string to bytes for SSH command input
+  ///
+  /// Uses GBK for Windows, UTF-8 for others
+  static List<int> encode(String text, {bool isWindows = false}) {
+    if (isWindows) {
+      try {
+        return gbk.encode(text);
+      } catch (e) {
+        Loggers.app.warning('GBK encode failed: $e, falling back to UTF-8');
+        return utf8.encode(text);
+      }
+    }
+    return utf8.encode(text);
+  }
+}