feat: Windows compatibility (#836)

* feat: win compatibility

* fix

* fix: uptime parse

* opt.: linux uptime accuracy

* fix: windows temperature fetching

* opt.

* opt.: powershell exec

* refactor: address PR review feedback and improve code quality

### Major Improvements:
- **Refactored Windows status parsing**: Broke down large `_getWindowsStatus` method into 13 smaller, focused helper methods for better maintainability and readability
- **Extracted system detection logic**: Created dedicated `SystemDetector` helper class to separate OS detection concerns from ServerProvider
- **Improved concurrency handling**: Implemented proper synchronization for server updates using Future-based locks to prevent race conditions

### Bug Fixes:
- **Fixed CPU percentage parsing**: Removed incorrect '*100' multiplication in BSD CPU parsing (values were already percentages)
- **Enhanced memory parsing**: Added validation and error handling to BSD memory fallback parsing with proper logging
- **Improved uptime parsing**: Added support for multiple Windows date formats and robust error handling with validation
- **Fixed division by zero**: Added safety checks in Swap.usedPercent getter

### Code Quality Enhancements:
- **Added comprehensive documentation**: Documented Windows CPU counter limitations and approach
- **Strengthened error handling**: Added detailed logging and validation throughout parsing methods
- **Improved robustness**: Enhanced BSD CPU parsing with percentage validation and warnings
- **Better separation of concerns**: Each parsing method now has single responsibility

### Files Changed:
- `lib/data/helper/system_detector.dart` (new): System detection helper
- `lib/data/model/server/cpu.dart`: Fixed percentage parsing and added validation
- `lib/data/model/server/memory.dart`: Enhanced fallback parsing and division-by-zero protection
- `lib/data/model/server/server_status_update_req.dart`: Refactored into 13 focused parsing methods
- `lib/data/provider/server.dart`: Improved synchronization and extracted system detection

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

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

* refactor: parse & shell fn struct

---------

Co-authored-by: Claude <noreply@anthropic.com>

lib/data/helper/system_detector.dart

@@ -0,0 +1,57 @@
+import 'package:dartssh2/dartssh2.dart';
+import 'package:fl_lib/fl_lib.dart';
+import 'package:server_box/data/model/server/server_private_info.dart';
+import 'package:server_box/data/model/server/system.dart';
+
+/// Helper class for detecting remote system types
+class SystemDetector {
+  /// Detects the system type of a remote server
+  /// 
+  /// First checks if a custom system type is configured in [spi].
+  /// If not, attempts to detect the system by running commands:
+  /// 1. 'ver' command to detect Windows
+  /// 2. 'uname -a' command to detect Linux/BSD/Darwin
+  /// 
+  /// Returns [SystemType.linux] as default if detection fails.
+  static Future<SystemType> detect(
+    SSHClient client,
+    Spi spi,
+  ) async {
+    // First, check if custom system type is defined
+    SystemType? detectedSystemType = spi.customSystemType;
+    if (detectedSystemType != null) {
+      dprint('Using custom system type ${detectedSystemType.name} for ${spi.oldId}');
+      return detectedSystemType;
+    }
+
+    try {
+      // Try to detect Windows systems first (more reliable detection)
+      final powershellResult = await client.run('ver 2>nul').string;
+      if (powershellResult.isNotEmpty &&
+          (powershellResult.contains('Windows') || powershellResult.contains('NT'))) {
+        detectedSystemType = SystemType.windows;
+        dprint('Detected Windows system type for ${spi.oldId}');
+        return detectedSystemType;
+      }
+
+      // Try to detect Unix/Linux/BSD systems
+      final unixResult = await client.run('uname -a').string;
+      if (unixResult.contains('Linux')) {
+        detectedSystemType = SystemType.linux;
+        dprint('Detected Linux system type for ${spi.oldId}');
+        return detectedSystemType;
+      } else if (unixResult.contains('Darwin') || unixResult.contains('BSD')) {
+        detectedSystemType = SystemType.bsd;
+        dprint('Detected BSD system type for ${spi.oldId}');
+        return detectedSystemType;
+      }
+    } catch (e) {
+      Loggers.app.warning('System detection failed for ${spi.oldId}: $e');
+    }
+
+    // Default fallback
+    detectedSystemType = SystemType.linux;
+    dprint('Defaulting to Linux system type for ${spi.oldId}');
+    return detectedSystemType;
+  }
+}