Even before she sees the name on the return address, Nancy Sloane knows who sent the letter — the Snoopy sticker that seals the envelope is a dead giveaway.It’s from Wesley Morgan, a 32-year-old fan of the comic strip “Peanuts” who’s been sending Snoopy-themed cards and letters across the country to ease the solitude of older adults in isolation due to the coronavirus.“He’s kept me