Oh man... that sucks! I'm so sorry.
Wow whoever said piston slap had it pretty close.
So I wonder... was that due to the ring gap or something else? I can't help but wonder if it was getting any oil. Gonna have to wait and see what Jeff says.
The piston is toast... but the jug may be salvageable with a good hone. Heck even if it gets bored out ever so slightly it may still be usable. Again, I'd run it all past Jeff.
FWIW, I appreciate you posting all of this... it will likely help many of us avoid a similar fate.
'12 Suzuki V-Strom DL650
'96 Suzuki DR650
'10 Kawasaki KLX351S #320