If bitcoin is indivisible, where does change come from? Let's say I want to give Alice .22 BTC. I currently have in my wallet 1 BTC. Because Bitcoin is indivisible, I have to spend the 1 BTC I have as input, and .78 BTC will be returned to me as change, while the other .22 BTC is sent to Alice. My question is how is this consistent with currency indivisibility? Is the .22 BTC and .78 technically created from the 1 BTC? Or is there change from another transaction? I'm just confused how it's indivisible but exact change can be created.
I like to suggest a mental model where the network is a metals forge:

You have a 1 oz gold coin stamped with your key on it, with your transaction you send it to the forge to be melted down and re-formed to two new coins, a .22 with Alice's key stamped on it and a .77 with a key of yours on it, and then the forge keeps the remainder for their fee.

You can't spend half your 1oz coin, but you can have the whole thing melted down into multiple, and perhaps many, parts.