How to reset the breaker on this smart dimmer light switch (switched receptacle)?
It was installed illegally.  That's why it failed.   

Your plugging a kettle in there was reasonable. 

Switched receptacles for lighting are legal.  What's illegal is placing a dimmer on a receptacle, and what happened to you is precisely the reason it is illegal.  

Now if you really, really want to dim a socket, you can use a magic, specially keyed receptacle that only accepts special "magic" lamp plugs (which you then put on your lamp).  That's what they should have done.  



You don't need to replace with an identical dimmer.  The rectangle shape is called a "Decora cover".  Most dimmers are compatible with it as are many plain switches. You'll need to decide whether to put a plain switch here; or put a dimmer and the above receptacle kit.  

Since this is the condo's mess-up, I would ask them to pay for it.