Across the smartphone industry, the invisible pressures of a global memory shortage have finally surfaced in the one place consumers feel them most — the price tag. Xiaomi, long a champion of affordable devices, announced this week that it will raise prices on select smartphones and tablets by as much as 25 percent beginning September 1, marking the moment a company built on competitive pricing concedes it can no longer shield its customers from the cost of components. The move is not an isolated corporate decision but a signal that the era of stable mid-range smartphone pricing may be giving