Crafting preview for weapons?
 

Is there any addon that would let me see what am I actually crafting in bigger than thumbnail-sized picture?

Did you search 'crafting preview' in the search bar? You might want to try that.

I can smell the tone all the way to here...
If you actually did that, you would know that addon is for armour only.

Not doable for now.

Did ZOS ever comment on the preview feature? I find it weird it's doable for armour and not weapons.

As the question, so the answer.
You could have added that you already found addon A and B, but they won't work for some reasons and have gotten a proper answer. ;)

The last statement from ZOS is that the system is currently being made and not ready. The armor preview addon is just unlocking one part that is already available via the API.