refactor(M03): extract ADT water scene finalizer

src/render/liquid/adt_water_scene_finalizer.gd

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+class_name AdtWaterSceneFinalizer
+extends RefCounted
+
+## Builds and attaches one ADT water subtree on the renderer main thread. The
+## supplied tile root owns the returned subtree; this service retains no state.
+
+const ADT_BUILDER_SCRIPT := preload("res://addons/mpq_extractor/loaders/adt_builder.gd")
+
+
+## Builds water from parsed ADT data and attaches it once to [param tile_root].
+## [param tile_origin_godot_units] is the existing Godot-world tile origin used
+## by [ADTBuilder]. When [param editor_owner] is non-null and is an ancestor,
+## ownership is assigned recursively for persisted Editor previews. Returns the
+## attached borrowed root, or null for empty/invalid input or dry ADT data.
+## This method mutates the SceneTree and must run on the main thread.
+func attach_water_scene(
+		water_data: Dictionary,
+		tile_origin_godot_units: Vector3,
+		tile_root: Node,
+		editor_owner: Node = null) -> Node3D:
+	if water_data.is_empty() or tile_root == null or not is_instance_valid(tile_root):
+		return null
+
+	var water_root: Node3D = ADT_BUILDER_SCRIPT.build_tile_water_scene(
+		water_data,
+		tile_origin_godot_units
+	)
+	if water_root == null:
+		return null
+
+	tile_root.add_child(water_root)
+	if editor_owner != null and is_instance_valid(editor_owner):
+		_assign_owner_recursive(water_root, editor_owner)
+	return water_root
+
+
+func _assign_owner_recursive(generated_node: Node, editor_owner: Node) -> void:
+	generated_node.owner = editor_owner
+	for child in generated_node.get_children():
+		_assign_owner_recursive(child, editor_owner)

src/render/liquid/adt_water_scene_finalizer.gd.uid

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+uid://ck4sdc8a3kg00