feat(worker): session skills SignalR surface + per-level persistence

src/ClaudeDo.Data/Repositories/ListRepository.cs

@@ -77,6 +77,7 @@ public sealed class ListRepository
             existing.SystemPrompt = config.SystemPrompt;
             existing.AgentPath = config.AgentPath;
             existing.MaxTurns = config.MaxTurns;
+            existing.SessionSkills = config.SessionSkills;
         }
         await _context.SaveChangesAsync(ct);
     }