fix: html entity syntax error in dashboard.gd, add @tool for editor preview

scenes/dashboard.gd

@@ -1,3 +1,4 @@
+@tool
 extends Control
 
 
@@ -7,6 +8,9 @@ var _modules: Array = []
 
 
 func _ready() -> void:
+	if Engine.is_editor_hint():
+		_set_background()
+		return
 	get_window().mode = Window.MODE_FULLSCREEN
 	_set_background()
 	_add_modules()
@@ -23,7 +27,6 @@ func _add_modules() -> void:
 	grid.place_module(cpu, 0, 0)
 	_modules.append(cpu)
 
-    # Start a timer to refresh all modules every second
 	var timer := Timer.new()
 	timer.timeout.connect(_refresh_modules)
 	timer.autostart = true
@@ -34,5 +37,5 @@ func _add_modules() -> void:
 func _refresh_modules() -> void:
 	var data: Dictionary = {}
 	for mod in _modules:
-        if is_instance_valid(mod) and mod.has_method("refresh"):
+		if is_instance_valid(mod) and mod.has_method("refresh"):
 			mod.refresh(data)

scripts/dashboard_grid.gd

@@ -1,3 +1,4 @@
+@tool
 extends Control
 class_name DashboardGrid