Add initial implementation of game mechanics and resources management

Scenes/Main/Main.cs

@@ -0,0 +1,44 @@
+using Godot;
+using ParasiticGod.Scripts.Core;
+using ParasiticGod.Scripts.Singletons;
+
+namespace ParasiticGod.Scenes.Main;
+
+public partial class Main : Node
+{
+    [Export] private Label _faithLabel;
+    [Export] private Label _followersLabel;
+    [Export] private Label _corruptionLabel;
+    [Export] private MiraclePanel _miraclePanel;
+    [Export] private Sprite2D _worldSprite;
+    [Export] private Color _deadWorldColor = new Color("#581845");
+
+    public override void _Ready()
+    {
+        GameBus.Instance.StateChanged += OnStateChanged;
+        
+        _miraclePanel.PopulateInitialButtons(GameBus.Instance.AllMiracles);
+    }
+
+    public override void _ExitTree()
+    {
+        GameBus.Instance.StateChanged -= OnStateChanged;
+    }
+
+    private void OnStateChanged(GameState newState)
+    {
+        _faithLabel.Text = $"Faith: {newState.Faith:F0} (+{newState.FaithPerSecond:F1}/s)";
+        _followersLabel.Text = $"Followers: {newState.Followers}";
+        _corruptionLabel.Text = $"Corruption: {newState.Corruption:F0}%";
+
+        UpdateWorldVisuals(newState.Corruption);
+    }
+
+    private void UpdateWorldVisuals(double corruption)
+    {
+        if (_worldSprite.Material is not ShaderMaterial shaderMaterial) return;
+        
+        var ratio = (float)corruption / 100.0f;
+        shaderMaterial.SetShaderParameter("corruption_level", ratio);
+    }
+}