Is there anything else I can possibly do to legally resolve this quickly,

No, not really, other than asking your neighbor if he has a spare key somewhere you can use to fix it.

or do I just have to suffer through this?

Unless you can resolve this with lawful permitted entry as per above, you probably have to suffer through it. It's unfortunately one of the costs of living in a condo - although peaceful enjoyment is assured, a week of a smoke detector chirping is probably going to fall just shy of HOA intervention.

There's probably not a police- or fire- department remedy here.

I'd try the HOA president again. If he's the on-premises responsible party for the HOA company he may have physical access rights that you don't have.

Sorry, I can relate - I know it sucks!