feat: add player-aware world interaction system

src/Features/Interactions/Godot/InteractionWorldController.cs

@@ -0,0 +1,65 @@
+using System;
+using System.Collections.Generic;
+using Game.Features.Interactions.Contracts;
+using Godot;
+
+namespace Game.Features.Interactions.Godot;
+
+public partial class InteractionWorldController : Node, IInteractionWorld
+{
+    public const string RegistryGroup = "interaction_world_registry";
+
+    private readonly Dictionary<InteractionTargetId, WorldInteractionController> _targets = [];
+
+    public override void _EnterTree()
+    {
+        AddToGroup(RegistryGroup);
+    }
+
+    public void RegisterSceneTargets()
+    {
+        foreach (Node node in GetTree().GetNodesInGroup(WorldInteractionController.InteractionGroup))
+        {
+            if (node is WorldInteractionController target)
+            {
+                Register(target);
+            }
+        }
+    }
+
+    public void Register(WorldInteractionController target)
+    {
+        if (_targets.TryGetValue(target.Id, out WorldInteractionController existing))
+        {
+            if (ReferenceEquals(existing, target))
+            {
+                return;
+            }
+
+            throw new InvalidOperationException($"Duplicate interaction target id: {target.Id}.");
+        }
+
+        _targets.Add(target.Id, target);
+        target.RegisterWith(this);
+    }
+
+    public void Unregister(InteractionTargetId targetId)
+    {
+        _targets.Remove(targetId);
+    }
+
+    public InteractionResult TryInteract(InteractionRequest request)
+    {
+        if (!_targets.TryGetValue(request.TargetId, out WorldInteractionController target))
+        {
+            return InteractionResult.Fail(InteractionStatus.TargetNotFound, $"Target {request.TargetId} was not found.");
+        }
+
+        if (!target.CanInteract)
+        {
+            return InteractionResult.Fail(InteractionStatus.Unavailable, "The target is not currently available.");
+        }
+
+        return target.Execute(request.PlayerId);
+    }
+}