Regarding Jango and his knowledge of the clones' purpose...
I'm looking for input from others, seeing as there are different legends and canon versions of how far Jango’s "awareness" goes.
Canon explanation hints at Jango not knowing the true purpose of the clones (we are going by a lack of information here). There are two instances:
Dooku approaches Jango on one of the moons of Bogden in Age of the Republic: Jango Fett (2019). He is in robes and hides his identity, going by the name of Tyranus. Dooku says "Think of it. A grand army of the republic.” So you'd think Jango is aware that his clones will be used as an army for the Republic. We can't be certain what else Dooku says because that is all the comic provides between them. Additionally, with his background now being more unclear after the events in season 2 of the Mandalorian, we can’t be sure how much he hates Jedi compared to legends Jango (survivor of the Battle of Galidraan, a legends event). If he doesn’t hate the Jedi as much, would he need to be informed of Order 66?
In Attack of the Clones (2002), Jango reveals that he was “recruited by a man called Tyranus on one of the moons of Bogden.” Once again, it is unclear if Jango originally knew the purpose of the clones. However, in the 10-year span of him being there, I wouldn't be surprised if he learned from the Kaminoans that a Jedi supposedly put the order in (key word supposedly). He would be able to realize that the story isn’t exactly straight and something may be amiss. Additionally, Jango oversaw the clones' training (according to the Wookieepedia, this is also hinted at in Age of Republic: Jango Fett) but how much, we don't know.
In legends, it’s indecisive, if not only unclear.
In Jango Fett: Open Seasons (2002-2003), Dooku outright tells Jango “In time, they will be instrumental in the destruction of the Jedi” when they are meeting in the fourth issue, referring to the clones. In this instance, Jango is aware that his clones will be used against the Jedi and I feel it safe to presume that he will be completely filled in on how it will happen (Order 66).
In Star Wars: Bounty Hunter (2002), Jango accepts a bounty under the pretense that it’s just a contest rewarding 5 million credits. In the end, when he wins, and Dooku arrives to personally congratulate Jango, revealing that he himself is a Force user, saying “No ordinary man can defeat one trained in the Jedi arts, especially one trained by me.” Dooku then offers Jango more than 5 million credits, but he has to come to Kamino to be cloned, where he will oversee the clones’ training and the clones will be programmed to be absolutely loyal. Another instance of no explanation of the clones’ true purpose.
Both canon and legends Wookieepedia pages about Jango Fett do not clarify if he was ever aware of the clones’ true purpose. On the Alpha-class Advanced Recon Commando page (legends only), it is stated that Jango could install his own personal orders in all of the Alpha ARCs, and the Alpha ARCs are reliable to the Jedi because Jango instructed them to follow their orders, but it is still not enough to gauge whether Jango knew or didn't know who would be giving those orders. I mention that because he could be aware of Order 66 since someone had to install the orders and he could install his own (example: an order to destroy all of the younger clones, should Kamino ever fall into the hands of the CIS. Alpha-17 almost carried out this order during the First Battle of Kamino). On the Cuy’val Dar page, Jango is quoted saying “This is a top-secret project" possibly hinting at knowing what the clones will be used for but it's not a guaranteed answer.
If anyone else has anything to say or wants to discuss this with me, please do! I'm open to private messages.