What are my options for correcting a bent aluminum fork?
It's not clear what is actually bent. From your picture, it is obvious what isn't bent: your fork is perfectly straight from the crown down to the drop outs.  Also, the boot which covers the stanchion seems to be quite suggestively aligned with the fork; the bend seems to occur at the top of the boot, just before the head tube.  If so, then it is in fact the shock's stanchion which is bent. That part may actually be a steel tube that inserts into the fork's crown. It would help to have a picture with the boot retracted or removed.

Here is what I mean, visually:



If that stanchion tube is bent, then on top of the steering problems, the suspension isn't going to work.  In this case, perhaps just that tube can be replaced instead of the whole fork?

That's the optimistic view. The more pessimistic view is that it's bent in two places. Let's rotate it back along these two points to illustrate:



In this edited image, I've straightened the boot-covered stanchion so it aligns with the head tube. Then a second bend where the crown meets the tube to add caster to the fork.

(Either way, it looks to me like substantially more than a 5-15 mm! That would barely be noticeable in the image. Do they mean 5-15 mm total displacement at the drop-out?)

Like anything else, this requires a careful inspection and diagnosis, so that a well-targeted and cost-effective repair can be performed.