chore(client): add gdUnit4 test framework addon

Vendor gdUnit4 for Godot 4 client testing (D-030).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

client/addons/gdUnit4/src/core/GdUnitProperty.gd

@@ -0,0 +1,81 @@
+class_name GdUnitProperty
+extends RefCounted
+
+
+var _name :String
+var _help :String
+var _type :int
+var _value :Variant
+var _value_set :PackedStringArray
+var _default :Variant
+
+
+func _init(p_name :String, p_type :int, p_value :Variant, p_default_value :Variant, p_help :="", p_value_set := PackedStringArray()) -> void:
+	_name = p_name
+	_type = p_type
+	_value = p_value
+	_value_set = p_value_set
+	_default = p_default_value
+	_help = p_help
+
+
+func name() -> String:
+	return _name
+
+
+func type() -> int:
+	return _type
+
+
+func value() -> Variant:
+	return _value
+
+
+func int_value() -> int:
+	return _value
+
+func value_as_string() -> String:
+	return _value
+
+
+func value_set() -> PackedStringArray:
+	return _value_set
+
+
+func is_selectable_value() -> bool:
+	return not _value_set.is_empty()
+
+
+func set_value(p_value: Variant) -> void:
+	match _type:
+		TYPE_STRING:
+			_value = str(p_value)
+		TYPE_BOOL:
+			_value = type_convert(p_value, TYPE_BOOL)
+		TYPE_INT:
+			_value = type_convert(p_value, TYPE_INT)
+		TYPE_FLOAT:
+			_value = type_convert(p_value, TYPE_FLOAT)
+		TYPE_DICTIONARY:
+			_value = type_convert(p_value, TYPE_DICTIONARY)
+		_:
+			_value = p_value
+
+
+func default() -> Variant:
+	return _default
+
+
+func category() -> String:
+	var elements := _name.split("/")
+	if elements.size() > 3:
+		return elements[2]
+	return ""
+
+
+func help() -> String:
+	return _help
+
+
+func _to_string() -> String:
+	return "%-64s %-10s %-10s (%s) help:%s set:%s" % [name(), type(), value(), default(), help(), _value_set]