They’ve arrived just when life seemed good again. Cold and flu germs, which nearly vanished for two years, are roaring back, according to doctors and federal disease-trackers. As we do less masking and more hugging and handshaking, “there is greater transmission of viruses,” said Dr. Jorge Salinas, hospital epidemiologist for Stanford Health Care. To be sure, COVID-19 is still spreading. But other long-lost ailments are catching up. At schools, “it’s not COVID,” said Salinas. “Everybody has a cough and one thing or another.” For a long time, masks and social distancing did a bang-up job of pro…