fix(worker): allow the done toggle from any non-Running status

MarkDoneAsync was Idle-only, so a finished task (typically a list-handler
run with no worktree to merge) could not be ticked off. Guard on Running
instead and cover the other statuses with tests.

tests/ClaudeDo.Worker.Tests/State/TaskStateServiceTests.cs

@@ -504,6 +504,24 @@ public sealed class TaskStateServiceTests : IDisposable
         Assert.Equal(TaskStatus.Running, await GetStatusAsync(id));
     }
 
+    // The done toggle is a manual affordance and must work from any non-Running status --
+    // notably WaitingForReview, where it deliberately skips the merge.
+    [Theory]
+    [InlineData(TaskStatus.Queued)]
+    [InlineData(TaskStatus.WaitingForReview)]
+    [InlineData(TaskStatus.WaitingForChildren)]
+    [InlineData(TaskStatus.Failed)]
+    [InlineData(TaskStatus.Cancelled)]
+    public async Task MarkDoneAsync_FromNonRunningStatus_TransitionsToDone(TaskStatus from)
+    {
+        var id = await SeedTaskAsync(from);
+
+        var result = await _sut.MarkDoneAsync(id, DateTime.UtcNow, default);
+
+        Assert.True(result.Ok);
+        Assert.Equal(TaskStatus.Done, await GetStatusAsync(id));
+    }
+
     [Fact]
     public async Task UnmarkDoneAsync_FromDone_TransitionsToIdle()
     {