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/model/server/server_private_info.dart

@@ -5,6 +5,7 @@ import 'package:freezed_annotation/freezed_annotation.dart';
 import 'package:server_box/data/model/app/error.dart';
 import 'package:server_box/data/model/server/custom.dart';
 import 'package:server_box/data/model/server/server.dart';
+import 'package:server_box/data/model/server/system.dart';
 import 'package:server_box/data/model/server/wol_cfg.dart';
 import 'package:server_box/data/provider/server.dart';
 import 'package:server_box/data/store/server.dart';
@@ -44,6 +45,9 @@ abstract class Spi with _$Spi {
     /// It only applies to SSH terminal.
     Map<String, String>? envs,
     @Default('') @JsonKey(fromJson: Spi.parseId) String id,
+
+    /// Custom system type (unix or windows). If set, skip auto-detection.
+    @JsonKey(includeIfNull: false) SystemType? customSystemType,
   }) = _Spi;
 
   factory Spi.fromJson(Map<String, dynamic> json) => _$SpiFromJson(json);
@@ -119,26 +123,25 @@ extension Spix on Spi {
   ///
   /// **NOT** the default value.
   static final example = Spi(
-      name: 'name',
-      ip: 'ip',
-      port: 22,
-      user: 'root',
-      pwd: 'pwd',
-      keyId: 'private_key_id',
-      tags: ['tag1', 'tag2'],
-      alterUrl: 'user@ip:port',
-      autoConnect: true,
-      jumpId: 'jump_server_id',
-      custom: ServerCustom(
-        pveAddr: 'http://localhost:8006',
-        pveIgnoreCert: false,
-        cmds: {
-          'echo': 'echo hello',
-        },
-        preferTempDev: 'nvme-pci-0400',
-        logoUrl: 'https://example.com/logo.png',
-      ),
-      id: 'id');
+    name: 'name',
+    ip: 'ip',
+    port: 22,
+    user: 'root',
+    pwd: 'pwd',
+    keyId: 'private_key_id',
+    tags: ['tag1', 'tag2'],
+    alterUrl: 'user@ip:port',
+    autoConnect: true,
+    jumpId: 'jump_server_id',
+    custom: ServerCustom(
+      pveAddr: 'http://localhost:8006',
+      pveIgnoreCert: false,
+      cmds: {'echo': 'echo hello'},
+      preferTempDev: 'nvme-pci-0400',
+      logoUrl: 'https://example.com/logo.png',
+    ),
+    id: 'id',
+  );
 
   bool get isRoot => user == 'root';
 }