test(data): Migration des Legacy-AppData-Verzeichnisses abdecken

Paths.MigrateLegacyAppDataRoot war ungetestet: Verschieben von ~/.todo-app
nach ~/.claudeDo, Pfad-Rewrite in den Config-Dateien und der No-Op-Fall.

tests/ClaudeDo.Data.Tests/LegacyAppDataRootMigrationTests.cs

@@ -0,0 +1,48 @@
+using ClaudeDo.Data;
+
+namespace ClaudeDo.Data.Tests;
+
+public class LegacyAppDataRootMigrationTests : IDisposable
+{
+    private readonly string _home = Path.Combine(Path.GetTempPath(), $"claudedo_home_{Guid.NewGuid():N}");
+
+    public void Dispose()
+    {
+        try { Directory.Delete(_home, true); } catch { /* best effort */ }
+    }
+
+    [Fact]
+    public void MovesLegacyRootAndRewritesConfigPaths()
+    {
+        var legacy = Path.Combine(_home, ".todo-app");
+        Directory.CreateDirectory(Path.Combine(legacy, "logs"));
+        File.WriteAllText(Path.Combine(legacy, "todo.db"), "db");
+        File.WriteAllText(Path.Combine(legacy, "worker.config.json"),
+            """{"db_path":"~/.todo-app/todo.db","log_root":"~/.todo-app/logs"}""");
+
+        Paths.MigrateLegacyAppDataRoot(_home);
+
+        var root = Path.Combine(_home, ".claudeDo");
+        Assert.False(Directory.Exists(legacy));
+        Assert.Equal("db", File.ReadAllText(Path.Combine(root, "todo.db")));
+        Assert.True(Directory.Exists(Path.Combine(root, "logs")));
+        Assert.Equal(
+            """{"db_path":"~/.claudeDo/todo.db","log_root":"~/.claudeDo/logs"}""",
+            File.ReadAllText(Path.Combine(root, "worker.config.json")));
+    }
+
+    [Fact]
+    public void LeavesLegacyRootAloneOnceTargetExists()
+    {
+        var legacy = Path.Combine(_home, ".todo-app");
+        var root = Path.Combine(_home, ".claudeDo");
+        Directory.CreateDirectory(legacy);
+        Directory.CreateDirectory(root);
+        File.WriteAllText(Path.Combine(root, "todo.db"), "new");
+
+        Paths.MigrateLegacyAppDataRoot(_home);
+
+        Assert.True(Directory.Exists(legacy));
+        Assert.Equal("new", File.ReadAllText(Path.Combine(root, "todo.db")));
+    }
+}