It’s here at last: the worst day of the year to be a Boston renter. Even if you’re not moving, September 1 passes like a shadow—a brief, ugly reminder of just how bad it is here to live in a home you don’t own. It’s not hard to count the ways: You can only really move in September and June; you have to pay a full month’s rent in useless broker’s fees; you’re locked into one yearlong lease after another; you live in fear of the next surprise rent hike; and finding a place that will let you have a cat, a dog, or sometimes even a goldfish just seems hopeless. It’s not merely personal misery, though: This is also bad for the city’s long-term health. Which is why as Boston booms and luxury apartments sprout like weeds, it’s high time for an official Boston Tenant’s Bill of Rights.