They can't, they'll have a nuisance lawsuit. Anything another property owner does that inhibits your enjoyment of your property (insanely bad smells, blinding lights, constant machinery running) makes them liable. If 311 doesn't help, that might be the next course of action.

They're not, but if underpaid, overworked, undertrained civil servants don't bother to go out and enforce it, call Budget Blinds or Automated Shade (you need shades and side... shield things to fully block out light - curtains always leave gaps above and to the sides).

Do you want to have a drawn out, lengthy and possibly expensive fight, that will ultimately end up with the state telling you that they can do on their property what they want to do, or, would you like to spend a couple hundred and fix the issue inside your house?