Restructure into core/ and content/official/

game/core/ui/modifier_tray.gd

@@ -0,0 +1,75 @@
+extends Control
+
+## Offers a set of random modifiers each round as draggable pieces.
+## Dropping one on the board applies it and consumes the whole set.
+
+const SectorSwatch := preload("res://core/ui/sector_swatch.gd")
+
+@export var drop_catcher: Control
+@export var pieces_per_round := 3
+@export var piece_size := Vector2(90, 110)
+@export var spacing := 24.0
+@export var bottom_margin := 30.0
+
+var _pieces: Array[Control] = []
+
+
+func _ready() -> void:
+	mouse_filter = Control.MOUSE_FILTER_IGNORE
+	spawn_round()
+
+
+func spawn_round() -> void:
+	_clear_pieces()
+
+	# ModRegistry is the autoload. (Was "ModifierCatalog" — renamed.)
+	var choices: Array = ModRegistry.pick_random(pieces_per_round)
+	if choices.is_empty():
+		push_warning("ModifierTray: registry returned no modifiers.")
+		return
+
+	for mod in choices:
+		var piece := Control.new()
+		piece.set_script(SectorSwatch)
+		piece.custom_minimum_size = piece_size
+		piece.size = piece_size
+		piece.modifier = mod
+		piece.paint_texture = mod.texture
+		piece.drop_catcher = drop_catcher
+		piece.tray = self
+		add_child(piece)
+		_pieces.append(piece)
+
+	_layout_pieces()
+
+
+func _layout_pieces() -> void:
+	var count := _pieces.size()
+	if count == 0:
+		return
+
+	var total_w := count * piece_size.x + (count - 1) * spacing
+	var screen := get_viewport_rect().size
+	var start_x := (screen.x - total_w) * 0.5
+	var y := screen.y - piece_size.y - bottom_margin
+
+	for i in count:
+		_pieces[i].position = Vector2(start_x + i * (piece_size.x + spacing), y)
+
+
+## Called by a piece when it lands successfully — the whole set is spent.
+func consume() -> void:
+	_clear_pieces()
+
+
+func _clear_pieces() -> void:
+	for p in _pieces:
+		if is_instance_valid(p):
+			p.queue_free()
+	_pieces.clear()
+
+
+# TESTING ONLY — SPACE rolls a new set.
+func _unhandled_input(event: InputEvent) -> void:
+	if event is InputEventKey and event.pressed and event.keycode == KEY_SPACE:
+		spawn_round()