test(scenes): ✅ Add test scene and test script for items queue validation

Co-Authored-By: Lilith Autocommit <noreply@atlilith.com>

src/game/engine/scenes/tests/items_queue_proof.gd

@@ -0,0 +1,118 @@
+extends Node
+## Proof scene for Task #11 (5.3): Items tab in production queue UI.
+##
+## Constructs an ItemList populated by `BuildableHelper.populate_items` against
+## a stub city that has smithy + alchemist_bench but is missing forge/tannery,
+## with a stockpile containing iron_ore but not cave_moss/direwolf_hide. This
+## yields a mix of enabled and disabled entries with explanatory tooltips:
+##
+##   ENABLED  iron_axe        (smithy + iron_ore + bronze_working all met)
+##   DISABLED healing_draught (no cave_moss, herbalism not researched)
+##   DISABLED dwarven_plate   (forge + tannery missing, no direwolf_hide,
+##                             steelworking not researched)
+##
+## Captures `user://screenshots/items_queue_proof.png` and quits.
+
+const BuildableHelper: GDScript = preload(
+	"res://engine/scenes/city/city_buildable_helper.gd"
+)
+
+
+## Stub player exposing the fields BuildableHelper reads: stockpile + techs.
+class PlayerStub:
+	extends RefCounted
+	var stockpile: RefCounted = null
+	var researched_techs: Array = ["bronze_working"]
+
+
+## Stub city exposing the fields BuildableHelper reads: buildings list.
+class CityStub:
+	extends RefCounted
+	var buildings: Array = ["smithy", "alchemist_bench"]
+
+
+func _ready() -> void:
+	DataLoader.load_theme("age-of-dwarves")
+
+	var stockpile: RefCounted = null
+	if ClassDB.class_exists("GdStockpile"):
+		stockpile = ClassDB.instantiate(&"GdStockpile") as RefCounted
+		if stockpile != null:
+			stockpile.call("add", "iron_ore", 4)
+	else:
+		push_error("[items_queue_proof] GdStockpile class missing")
+
+	var player: PlayerStub = PlayerStub.new()
+	player.stockpile = stockpile
+	var city: CityStub = CityStub.new()
+
+	var root: PanelContainer = PanelContainer.new()
+	root.anchor_right = 1.0
+	root.anchor_bottom = 1.0
+	add_child(root)
+
+	var margin: MarginContainer = MarginContainer.new()
+	margin.add_theme_constant_override("margin_left", 24)
+	margin.add_theme_constant_override("margin_top", 24)
+	margin.add_theme_constant_override("margin_right", 24)
+	margin.add_theme_constant_override("margin_bottom", 24)
+	root.add_child(margin)
+
+	var vbox: VBoxContainer = VBoxContainer.new()
+	vbox.add_theme_constant_override("separation", 8)
+	margin.add_child(vbox)
+
+	var title: Label = Label.new()
+	title.text = "Items Queue — Smithy + Alchemist's Bench (proof)"
+	title.add_theme_color_override("font_color", Color(1.0, 0.92, 0.7, 1))
+	title.add_theme_font_size_override("font_size", 18)
+	vbox.add_child(title)
+
+	var subtitle: Label = Label.new()
+	subtitle.text = (
+		"City has: smithy, alchemist_bench    "
+		+ "Stockpile: iron_ore × 4    "
+		+ "Techs: bronze_working"
+	)
+	subtitle.add_theme_color_override("font_color", Color(0.78, 0.74, 0.62, 1))
+	subtitle.add_theme_font_size_override("font_size", 12)
+	vbox.add_child(subtitle)
+
+	var list: ItemList = ItemList.new()
+	list.custom_minimum_size = Vector2(680, 420)
+	list.add_theme_color_override("font_color", Color(0.94, 0.91, 0.82, 1))
+	list.add_theme_color_override("font_selected_color", Color(1, 1, 1, 1))
+	list.add_theme_font_size_override("font_size", 14)
+	vbox.add_child(list)
+
+	BuildableHelper.populate_items(list, city, player)
+
+	var legend: Label = Label.new()
+	legend.text = (
+		"Greyed entries are disabled. Hover for the missing-requirement tooltip."
+	)
+	legend.add_theme_color_override("font_color", Color(0.7, 0.7, 0.6, 1))
+	legend.add_theme_font_size_override("font_size", 11)
+	vbox.add_child(legend)
+
+	for i: int in list.item_count:
+		var meta: Dictionary = list.get_item_metadata(i) as Dictionary
+		print(
+			"[items_queue_proof] %s  disabled=%s  reason=%s"
+			% [meta.get("id", "?"), list.is_item_disabled(i), meta.get("reason", "")]
+		)
+
+	await get_tree().create_timer(0.6).timeout
+	_capture()
+	await get_tree().create_timer(0.2).timeout
+	get_tree().quit()
+
+
+func _capture() -> void:
+	var img: Image = get_viewport().get_texture().get_image()
+	var dir: String = "user://screenshots"
+	if not DirAccess.dir_exists_absolute(dir):
+		DirAccess.make_dir_recursive_absolute(dir)
+	var path: String = "%s/items_queue_proof.png" % dir
+	img.save_png(path)
+	print("[items_queue_proof] saved ", ProjectSettings.globalize_path(path))

src/game/engine/scenes/tests/items_queue_proof.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://engine/scenes/tests/items_queue_proof.gd" id="1"]
+
+[node name="ItemsQueueProof" type="Node"]
+script = ExtResource("1")