feat(data): add ListRepository.DeleteConfigAsync

src/ClaudeDo.Data/Repositories/ListRepository.cs

@@ -88,4 +88,12 @@ public sealed class ListRepository
         }
         await _context.SaveChangesAsync(ct);
     }
+
+    public async Task<bool> DeleteConfigAsync(string listId, CancellationToken ct = default)
+    {
+        var affected = await _context.ListConfigs
+            .Where(c => c.ListId == listId)
+            .ExecuteDeleteAsync(ct);
+        return affected > 0;
+    }
 }