Add tier management system with JSON loading; refactor PopulationVisualizer for category handling

Scripts/Core/TierDefinition.cs

@@ -5,6 +5,7 @@ namespace ParasiticGod.Scripts.Core;
 [GlobalClass]
 public partial class TierDefinition : Resource
 {
-    [Export] public PackedScene Scene { get; private set; }
-    [Export] public long Threshold { get; private set; }
+    [Export] public PackedScene Scene { get; set; }
+    [Export] public long Threshold { get; set; }
+    [Export] public Follower.FollowerTier TierEnum { get; set; }
 }

Scripts/Core/TierDto.cs

@@ -0,0 +1,15 @@
+using System.Collections.Generic;
+
+namespace ParasiticGod.Scripts.Core;
+
+public class TierDto
+{
+    public Follower.FollowerTier TierEnum { get; set; }
+    public long Threshold { get; set; }
+    public string ScenePath { get; set; }
+}
+
+public class TierListDto
+{
+    public List<TierDto> Tiers { get; set; }
+}

Scripts/Core/TierDto.cs.uid

@@ -0,0 +1 @@
+uid://4432c2r3q5vv

Scripts/Core/TierLoader.cs

@@ -0,0 +1,42 @@
+using System.Collections.Generic;
+using System.Linq;
+using Godot;
+using Newtonsoft.Json;
+
+namespace ParasiticGod.Scripts.Core;
+
+public static class TierLoader
+{
+    public static List<TierDefinition> LoadTiersFromFile(string filePath)
+    {
+        var loadedTiers = new List<TierDefinition>();
+        
+        var fileContent = FileAccess.GetFileAsString(filePath);
+        if (string.IsNullOrEmpty(fileContent))
+        {
+            GD.PushError($"Failed to read tier file or file is empty: {filePath}");
+            return loadedTiers;
+        }
+
+        var tierListDto = JsonConvert.DeserializeObject<TierListDto>(fileContent);
+        if (tierListDto?.Tiers == null)
+        {
+            GD.PushError($"Failed to deserialize tier list JSON or 'Tiers' array is missing: {filePath}");
+            return loadedTiers;
+        }
+
+        foreach (var dto in tierListDto.Tiers)
+        {
+            var tierDef = new TierDefinition
+            {
+                Threshold = dto.Threshold,
+                TierEnum = dto.TierEnum,
+                Scene = GD.Load<PackedScene>(dto.ScenePath) 
+            };
+            loadedTiers.Add(tierDef);
+        }
+
+        GD.Print($"Loaded {loadedTiers.Count} follower tiers from {filePath}");
+        return loadedTiers.OrderBy(t => t.Threshold).ToList();
+    }
+}

Scripts/Core/TierLoader.cs.uid

@@ -0,0 +1 @@
+uid://hgx8qu7etqhm