Initial commit: ClawdDotNet

Import des bestehenden Projektstands in Git.
- .NET 10 WinForms Anwendung (Multi-Agent / Tool-System)
- .gitignore fuer Build-Artefakte, Secrets und Runtime-Daten ergaenzt

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/ClawdDotNet.Core/Tools/ToolResult.cs

@@ -0,0 +1,12 @@
+namespace ClawdDotNet.Core.Tools;
+
+public sealed record ToolResult(
+    bool Success,
+    string Content,
+    string? ErrorMessage = null
+)
+{
+    public static ToolResult Ok(string content) => new(true, content);
+
+    public static ToolResult Fail(string error) => new(false, "", error);
+}