As millions of Brits gear up for a festive flight extravaganza, travel experts issue a stark warning: the joy of gifting could turn into a financial nightmare, with unexpected baggage fees tipping the scales at a hefty £100 or more. Navigating the labyrinthine rules of airline check-in, passengers may be unaware that even wrapped Christmas presents fall prey to the stringent 10-item 100ml liquid and electronic hand luggage…