feat: net10.0 Linux Console mode — zero Mono, 0 compile errors

Migrated from net48 (.NET Framework) to net10.0 (cross-platform):
- All 14 csproj: net48 → net10.0, WindowsDesktop SDK → Microsoft.NET.Sdk
- Excluded WinForms files (Form/**, DebugControl, GameControl, etc.)
- Excluded DB modules (GameDAL db/Sql/**, MrWu DB files)
- Excluded server runtime files (GameBase, GlobalSever managers, GameNetModule stubs)
- Added minimal stubs (GameDoStub.cs, NamespaceStubs.cs, ServerCoreStubs.cs)
- Created hjha-console entry project
- Fixed hardcoded Windows path → ./test/ directory
- Updated global.json to SDK 10.0.109

Console test mode: PdkGameMain(null).Test() → 发牌→包庄→打牌→结算
Verified: dotnet build 0 errors, dotnet run outputs game state machine

PdkFriendServer/Logic/PdkGameMain.cs

@@ -730,7 +730,14 @@ namespace PdkFriendServer.Logic
             {
                 File.Delete("output.txt");
             }
-            foreach (string file in Directory.GetFiles(@"C:\Users\Administrator\Desktop\temp\test"))
+            string testDir = !string.IsNullOrWhiteSpace(path) 
+                ? path 
+                : "./test";
+            if (!Directory.Exists(testDir))
+            {
+                Directory.CreateDirectory(testDir);
+            }
+            foreach (string file in Directory.GetFiles(testDir))
             {
                 File.Delete(file);
             }