If you buy Apple's new folding iPhone this Friday, you'll open and close it around 10,000 times by the end of January. A YouTuber named Tim Pan already did that to one. He folded it 500 times by hand, strapped it to a machine for 10,000 more, then dropped the temperature to -4°F and ran another 1,000. That January date comes from Samsung's math. Samsung figures people fold these phones about 100 times a day, and 100 a day for 100 days gets you to 10,000. You should care because Apple charges…