s&box Cleanup System: Tag-Based Removal with ICleanupEvents

public partial class CleanupSystem : Component
{
    public static CleanupSystem Current { get; private set; }
    
    // Track original map objects for restoration
    private List<GameObject> _originalObjects = new();
    private HashSet<Guid> _originalIds = new();
    
    protected override void OnStart()
    {
        Current = this;
        
        // Record original scene objects on startup
        foreach (var obj in Scene.GetAllObjects(true))
        {
            _originalObjects.Add(obj);
            _originalIds.Add(obj.Id);
        }
    }
    
    [ConCmd("cleanup", ConVarFlags.Cheat)]
    public static void CleanupCommand()
    {
        if (!Networking.IsHost) return;
        Current?.DoCleanup();
    }
}

public void DoCleanup()
{
    if (!Networking.IsHost) return;
    
    int removedCount = 0;
    int restoredCount = 0;
    
    // Find all removable objects
    var objectsToClean = Scene.GetAllObjects(true)
        .Where(obj => obj.Tags.Has("removable"))
        .ToList();
    
    foreach (var obj in objectsToClean)
    {
        if (!obj.IsValid()) continue;
        if (_originalIds.Contains(obj.Id)) continue;  // Don't remove original map objects
        
        // Check if object was spawned by a player (has Ownable)
        if (obj.Components.Get<Ownable>() is { } ownable)
        {
            obj.Destroy();
            removedCount++;
        }
    }
    
    // Restore any modified original objects
    foreach (var original in _originalObjects)
    {
        if (!original.IsValid())
        {
            // Object was destroyed - could restore from prefab if needed
            restoredCount++;
        }
        else
        {
            // Reset position/rotation if moved significantly
            // (implementation depends on save system integration)
        }
    }
    
    // Notify via GameManager's ICleanupEvents
    Scene.RunEvent<ICleanupEvents>(x => x.OnCleanup(removedCount, restoredCount));
}

public interface ICleanupEvents : ISceneEvent<ICleanupEvents>
{
    void OnCleanup(int removedObjects, int restoredObjects);
}

public sealed partial class GameManager : ICleanupEvents
{
    void ICleanupEvents.OnCleanup(int removedObjects, int restoredObjects)
    {
        Notices.AddNotice("cleaning_services", Color.Green, 
            $"Cleanup! Removed {removedObjects} objects, restored {restoredObjects} objects.");
    }
}

// When spawning objects, tag as removable
public void DoSpawn(Transform transform)
{
    var objects = await Spawner.Spawn(transform, player);
    
    foreach (var go in objects)
    {
        go.Tags.Add("removable");
        
        // Add ownership for multiplayer
        Ownable.Set(go, player.Network.Owner);
        go.NetworkSpawn();
    }
}

// Constraints also get removable tag
void CreateConstraint(GameObject obj1, GameObject obj2)
{
    obj1.Tags.Add("removable");
    obj2.Tags.Add("removable");
    // ...
}