Berkshire's "return to buying stocks" is really two things. A $10 billion Alphabet bet that 95-year-old Buffett initiated himself, and $7.8 billion of Abel buying back Berkshire's own shares. The headline math is real. $23.5 billion of stock purchases against $3.7 billion of sales, ending a 14-quarter selling streak that built the largest cash pile in corporate history. But strip out Alphabet and the net buying comes to roughly $10 billion against $344 billion of cash. A 3% deployment rate.…