What is the jaylib equivalent for texture.width ?

How does one access a texture's inner fields, for example `tex.width` and `tex.height` ?

```
(def img (load-image-1 "raylib.png"))
(def tex (load-texture-from-image img))
(unload-image img)

# This doesn't work
(def w (get tex :width))
(def h (get tex :height))
```

Review the jaylib API around load-texture-from-image and the Texture value, then check how equivalent field access is exposed. Done means confirming how to obtain width and height and recording an example or documentation reference for the issue.

Written by the indexing model from the issue text.