fix(worker): fix Bandel ticket sync and reactivate the integration

The status PATCH needs statusName alongside statusId or the API 400s,
so every write-back had been silently failing. The board's flat
assigneeName is null on every live ticket; the real assignee list is
ticketAssignees[]. Import now also picks up In Bearbeitung tickets,
not just Offen ones.

Both issues are live-verified against the real API, so the feature
flag flips back on.

tests/ClaudeDo.Worker.Tests/Tickets/TicketStatusMapTests.cs

@@ -28,6 +28,27 @@ public sealed class TicketStatusMapTests
             Assert.NotEqual(1, TicketStatusMap.ToTicketStatus(status));
     }
 
+    // Der PATCH-Body braucht statusName; ein leerer Name wäre ein 400 der API.
+    [Fact]
+    public void NameOf_is_never_empty_for_any_status_we_write()
+    {
+        foreach (var status in Enum.GetValues<TaskStatus>())
+        {
+            if (TicketStatusMap.ToTicketStatus(status) is not int id) continue;
+            Assert.False(string.IsNullOrWhiteSpace(TicketStatusMap.NameOf(id)));
+        }
+
+        Assert.False(string.IsNullOrWhiteSpace(TicketStatusMap.NameOf(99)));
+    }
+
+    [Theory]
+    [InlineData(1, "Offen")]
+    [InlineData(2, "InBearbeitung")]
+    [InlineData(3, "Fertig")]
+    [InlineData(4, "Archiviert")]
+    public void NameOf_matches_the_api_status_list(int id, string expected)
+        => Assert.Equal(expected, TicketStatusMap.NameOf(id));
+
     [Theory]
     [InlineData("bandel:1234", 1234)]
     [InlineData("BANDEL:7", 7)]