fix(worker): interaktive Session ohne Arbeitsverzeichnis im User-Verzeichnis starten

Eine manuelle Liste (Erinnerungen) hat kein WorkingDir. BuildForTaskAsync
warf dafuer bisher "no working directory configured", die interaktive
Session liess sich also nicht oeffnen. Jetzt faellt der Pfad auf das
User-Verzeichnis zurueck; Session-Skills werden dort bewusst nicht
geseedet, weil das Ziel das echte ~/.claude/skills waere.

tests/ClaudeDo.Worker.Tests/Runner/InteractiveLaunchSpecServiceTests.cs

@@ -220,8 +220,15 @@ public sealed class InteractiveLaunchSpecServiceTests : IDisposable
     }
 
     [Fact]
-    public async Task BuildForTaskAsync_NoWorktreeRow_NoWorkingDirConfigured_ThrowsInvalidOperation()
+    public async Task BuildForTaskAsync_NoWorktreeRow_NoWorkingDirConfigured_OpensInUserHomeWithoutSeedingSkills()
     {
+        _registry.Installed.Add(new SessionSkillEntity
+        {
+            Name = "installed-skill", SourceUrl = "https://example.com/x.git",
+            PinnedRef = "abc", Subpath = "skills/installed-skill", Description = "d",
+            AddedAt = DateTimeOffset.UtcNow,
+        });
+
         var listId = await SeedListAsync();
         using (var ctx = _db.CreateContext())
         {
@@ -230,11 +237,18 @@ public sealed class InteractiveLaunchSpecServiceTests : IDisposable
             await ctx.SaveChangesAsync();
         }
         var taskId = Guid.NewGuid().ToString();
-        await SeedTaskAsync(taskId, listId, TaskStatus.Idle);
+        await SeedTaskAsync(taskId, listId, TaskStatus.Idle,
+            sessionSkillsJson: "[\"installed-skill\"]");
 
         var svc = BuildService();
-        await Assert.ThrowsAsync<InvalidOperationException>(
-            () => svc.BuildForTaskAsync(taskId, CancellationToken.None));
+        var spec = await svc.BuildForTaskAsync(taskId, CancellationToken.None);
+
+        Assert.Equal(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), spec.Cwd);
+        // Seeding here would copy into the user's REAL ~/.claude/skills.
+        Assert.Empty(_seeder.Calls);
+
+        using var readCtx = _db.CreateContext();
+        Assert.Null(await new WorktreeRepository(readCtx).GetByTaskIdAsync(taskId));
     }
 
     [Fact]