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/State/IStateStore.cs

@@ -0,0 +1,8 @@
+namespace ClawdDotNet.Core.State;
+
+public interface IStateStore
+{
+    Task<string?> GetAsync(string key, CancellationToken ct);
+    Task SetAsync(string key, string value, CancellationToken ct);
+    Task DeleteAsync(string key, CancellationToken ct);
+}