feat(ui): Listen-Einstellungen — Checkbox fuer serialize_on_file_overlap

Das Flag war bisher nur ueber MCP set_list_config erreichbar. UpdateListConfigDto
fuehrt es tri-state (null = gespeicherten Wert behalten), damit nur das
Listen-Modal es setzen/loeschen kann und kein anderer Aufrufer es per Omission
verliert.

src/ClaudeDo.Worker/External/ConfigMcpTools.cs

@@ -104,8 +104,8 @@ public sealed class ConfigMcpTools
 
         // Fields this tool doesn't expose but that live on the same row. They must survive every
         // write here — ListRepository.SetConfigAsync copies the entity verbatim, so anything left
-        // at its default would silently reset (SerializeOnFileOverlap in particular has no UI
-        // affordance at all, so a reset is invisible until tasks stop serializing).
+        // at its default would silently reset (a SerializeOnFileOverlap reset only shows up as
+        // tasks no longer serializing, long after this write).
         var hasUnrelatedSettings = existing is not null
             && (existing.SessionSkills is not null || existing.SerializeOnFileOverlap);
 

src/ClaudeDo.Worker/Hub/WorkerHub.cs

@@ -545,13 +545,13 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
         var sessionSkills = SkillsToJson(dto.SessionSkills);
         var verifyCommand = dto.VerifyCommand.NullIfBlank();
 
-        // Preserve SerializeOnFileOverlap: it has no UI/hub affordance yet (set via
-        // set_list_config or directly against ListConfigEntity), so a save from this path
-        // must not silently drop it -- neither by deleting the row nor by overwriting it.
+        // A null SerializeOnFileOverlap means "leave it as stored" — only the list-settings modal
+        // owns that field, so every other caller must not drop it (neither by deleting the row nor
+        // by overwriting it: SetConfigAsync copies the entity verbatim).
         var existing = await repo.GetConfigAsync(dto.ListId);
-        var hasUnrelatedSettings = existing?.SerializeOnFileOverlap ?? false;
+        var serializeOnFileOverlap = dto.SerializeOnFileOverlap ?? existing?.SerializeOnFileOverlap ?? false;
 
-        if (model is null && systemPrompt is null && agentPath is null && dto.MaxTurns is null && sessionSkills is null && verifyCommand is null && !hasUnrelatedSettings)
+        if (model is null && systemPrompt is null && agentPath is null && dto.MaxTurns is null && sessionSkills is null && verifyCommand is null && !serializeOnFileOverlap)
         {
             await repo.DeleteConfigAsync(dto.ListId);
         }
@@ -566,7 +566,7 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
                 MaxTurns = dto.MaxTurns,
                 SessionSkills = sessionSkills,
                 VerifyCommand = verifyCommand,
-                SerializeOnFileOverlap = existing?.SerializeOnFileOverlap ?? false,
+                SerializeOnFileOverlap = serializeOnFileOverlap,
             });
         }
 
@@ -579,7 +579,7 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
         var repo = new ListRepository(ctx);
         var config = await repo.GetConfigAsync(listId);
         if (config is null) return null;
-        return new ListConfigDto(config.Model, config.SystemPrompt, config.AgentPath, config.MaxTurns, SkillsFromJson(config.SessionSkills), config.VerifyCommand);
+        return new ListConfigDto(config.Model, config.SystemPrompt, config.AgentPath, config.MaxTurns, SkillsFromJson(config.SessionSkills), config.VerifyCommand, config.SerializeOnFileOverlap);
     }
 
     public async Task<SetTaskStatusResultDto> SetTaskStatus(string taskId, string status)