When Robert Hernandez unpacked his meager belongings into one of San Jose’s celebrated tiny homes, finally getting a bed and access to a shower after more than a decade on the street, he had reason to be elated. After all, tiny homes have become the hot new thing in the fight to end homelessness. The simple dwellings have multiplied across the Bay Area in the last few years and have been touted in splashy news conferences by everyone from the region’s big city mayors to Gov. Gavin Newsom as a salve to one of California’s thorniest problems. But even after 55-year-old Hernandez moved into his t…