Add enum for Selection method

src/Managing.Application/GeneticService.cs

@@ -203,7 +203,7 @@ public class GeneticService : IGeneticService
         int populationSize,
         int generations,
         double mutationRate,
-        string selectionMethod,
+        GeneticSelectionMethod selectionMethod,
         int elitismPercentage,
         double maxTakeProfit,
         List<IndicatorType> eligibleIndicators)
@@ -422,13 +422,13 @@ public class GeneticService : IGeneticService
         }
     }
 
-    private ISelection GetSelection(string selectionMethod)
+    private ISelection GetSelection(GeneticSelectionMethod selectionMethod)
     {
-        return selectionMethod.ToLower() switch
+        return selectionMethod switch
         {
-            "tournament" => new TournamentSelection(),
-            "roulette" => new RouletteWheelSelection(),
-            "fitness-weighted" => new RankSelection(), // Use rank selection as approximation
+            GeneticSelectionMethod.Tournament => new TournamentSelection(),
+            GeneticSelectionMethod.Roulette => new RouletteWheelSelection(),
+            GeneticSelectionMethod.FitnessWeighted => new RankSelection(), // Use rank selection as approximation
             _ => new TournamentSelection()
         };
     }