Phase 2-3: UI layout, theme switching, CRUD tools, process execution

- Phase 2: MainWindow 3-section layout (sidebar/content/log bar), Dark/Light theme with ThemeHelper, MainViewModel with ObservableProperty/RelayCommand, tool card filtering by search + category

- Phase 3: ToolEditWindow for add/edit tools, ProcessExecutionService (Process.Start + error handling), double-click + right-click context menu (run/edit), path browse dialog

- Bugfix: ContextMenu commands now use PlacementTarget.Tag binding (ContextMenu in separate visual tree)

- Bugfix: StaticResource converters moved to XAML before DataTemplate to fix XamlParseException on tool card render

- Bugfix: Pure filenames (no path separators) treated as PATH commands, not marked invalid

- Bugfix: RefreshData preserves SelectedCategory; Load() catches all exceptions; Save() wrapped in try-catch; auto-scroll log to newest entry

- Tests: xUnit project with 55 tests covering models, services, converters, and view models

PersonalToolBox.Tests/Services/JsonDataServiceTests.cs

@@ -0,0 +1,194 @@
+using System.IO;
+using Moq;
+using PersonalToolBox.Models;
+using PersonalToolBox.Services;
+
+namespace PersonalToolBox.Tests.Services;
+
+public class JsonDataServiceTests
+{
+    private readonly Mock<ILogService> _logServiceMock = new();
+    private readonly string _testDir;
+
+    public JsonDataServiceTests()
+    {
+        _testDir = Path.Combine(Path.GetTempPath(), $"toolbox_test_{Guid.NewGuid():N}");
+        Directory.CreateDirectory(_testDir);
+    }
+
+    [Fact]
+    public void Load_FileNotExists_CreatesDefaultConfig()
+    {
+        // Use a path that doesn't exist
+        var configPath = Path.Combine(_testDir, "nonexistent.json");
+        var service = CreateService(configPath);
+
+        service.Load();
+
+        Assert.NotNull(service.Config);
+        Assert.Equal("Dark", service.Config.Theme);
+        Assert.Empty(service.Config.Tools);
+
+        // Verify warning was logged
+        VerifyLog(LogLevel.Info, "默认配置");
+    }
+
+    [Fact]
+    public void Save_ThenLoad_PreservesData()
+    {
+        var configPath = Path.Combine(_testDir, "config.json");
+        var service = CreateService(configPath);
+
+        service.Config.Theme = "Light";
+        service.Config.Categories.Add(new Category { Id = "1", Name = "dev" });
+        service.Config.Tools.Add(new ToolItem
+        {
+            Name = "TestTool",
+            ExecutablePath = Path.Combine(_testDir, "test.exe")
+        });
+
+        service.Save();
+
+        // Load into a new service
+        var service2 = CreateService(configPath);
+        service2.Load();
+
+        Assert.Equal("Light", service2.Config.Theme);
+        Assert.Single(service2.Config.Categories);
+        Assert.Equal("dev", service2.Config.Categories[0].Name);
+        Assert.Single(service2.Config.Tools);
+        Assert.Equal("TestTool", service2.Config.Tools[0].Name);
+    }
+
+    [Fact]
+    public void Load_InvalidPath_ToolSetToInvalid()
+    {
+        var configPath = Path.Combine(_testDir, "config.json");
+        var service = CreateService(configPath);
+
+        service.Config.Tools.Add(new ToolItem
+        {
+            Name = "MissingTool",
+            ExecutablePath = @"C:\definitely\does\not\exist.exe"
+        });
+
+        service.Save();
+
+        var service2 = CreateService(configPath);
+        service2.Load();
+
+        var tool = service2.Config.Tools[0];
+        Assert.False(tool.IsValid);
+        VerifyLog(LogLevel.Warning, "路径失效");
+    }
+
+    [Fact]
+    public void Load_ValidPath_ToolRemainsValid()
+    {
+        var configPath = Path.Combine(_testDir, "config.json");
+        var service = CreateService(configPath);
+
+        // Create a real temp file
+        var tempFile = Path.Combine(_testDir, "real_tool.exe");
+        File.WriteAllText(tempFile, "dummy");
+
+        service.Config.Tools.Add(new ToolItem
+        {
+            Name = "RealTool",
+            ExecutablePath = tempFile
+        });
+
+        service.Save();
+
+        var service2 = CreateService(configPath);
+        service2.Load();
+
+        var tool = service2.Config.Tools[0];
+        Assert.True(tool.IsValid);
+    }
+
+    [Fact]
+    public void Load_UrlPath_AlwaysValid()
+    {
+        var configPath = Path.Combine(_testDir, "config.json");
+        var service = CreateService(configPath);
+
+        service.Config.Tools.Add(new ToolItem
+        {
+            Name = "WebTool",
+            ExecutablePath = "https://example.com/tool"
+        });
+
+        service.Save();
+
+        var service2 = CreateService(configPath);
+        service2.Load();
+
+        var tool = service2.Config.Tools[0];
+        Assert.True(tool.IsValid);
+    }
+
+    [Fact]
+    public void Load_EmptyExecutablePath_SkipsValidation()
+    {
+        var configPath = Path.Combine(_testDir, "config.json");
+        var service = CreateService(configPath);
+
+        service.Config.Tools.Add(new ToolItem
+        {
+            Name = "NoPathTool",
+            ExecutablePath = ""
+        });
+
+        service.Save();
+
+        var service2 = CreateService(configPath);
+        service2.Load();
+
+        var tool = service2.Config.Tools[0];
+        Assert.True(tool.IsValid);
+    }
+
+    [Fact]
+    public void Load_CorruptedJson_LogsErrorAndUsesDefaults()
+    {
+        var configPath = Path.Combine(_testDir, "config.json");
+        File.WriteAllText(configPath, "this is not json {{{");
+
+        var service = CreateService(configPath);
+        service.Load();
+
+        Assert.NotNull(service.Config);
+        Assert.Equal("Dark", service.Config.Theme);
+        VerifyLog(LogLevel.Error, "解析失败");
+    }
+
+    // ───────────────────────────── helpers ─────────────────────────────
+
+    private JsonDataService CreateService(string filePath)
+    {
+        var service = new JsonDataService(_logServiceMock.Object);
+        // Replace the file path via reflection
+        typeof(JsonDataService)
+            .GetField("_filePath", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance)?
+            .SetValue(service, filePath);
+        return service;
+    }
+
+    private void VerifyLog(LogLevel level, string fragment)
+    {
+        // 根据日志级别验证对应方法被调用
+        switch (level)
+        {
+            case LogLevel.Info:
+                _logServiceMock.Verify(x => x.Info(It.Is<string>(s => s.Contains(fragment))), Times.AtLeastOnce);
+                break;
+            case LogLevel.Warning:
+                _logServiceMock.Verify(x => x.Warning(It.Is<string>(s => s.Contains(fragment))), Times.AtLeastOnce);
+                break;
+            case LogLevel.Error:
+                _logServiceMock.Verify(x => x.Error(It.Is<string>(s => s.Contains(fragment))), Times.AtLeastOnce);
+                break;
+        }
+    }
+}