Yes, it ends when you use a turn-ending action like shooting, hunker, overwatch etc.
Try using the Super Unit Mode in the trainer. Alternatively, console command of "ToggleGodMode" works as well.
Apologies for the double post. Not sure how to quote twice in a message.
Tiredness is related to your soldier's will. I noticed that once you change or increase the will, it does seem to affect their tiredness.
Alternatively, you can get that achievement for sending all tired soldiers out and not getting wounded. 😐
The facility you are looking for is the Training Center, it handles bonds, resetting abilities, and ability point usage.
Near the bottom of the screen will be a button called Train Abilities, choose that, then pick any soldier that has been promoted at least twice, and you will have the option to spend AP to buy the other perk you skipped as well as possible new perks that were previously AWC perks.
You will see the screen when promoting your faction soldiers.
Not really sure how to add a save game file but will try.
The new AP points are for the new soldier classes that were introduced into the Chosen expansion: Reaper, Skirmisher, or Templar. See here (scroll down for a screen shot):
There are two kinds of AP points: the soldier AP points or the Xcom AP points. The soldier AP points don't matter for a trainer. The XCOM AP points are "general" AP Points that can be used to upgrade ANY of the three new classes. You can get them after doing certain covert actions once you've built the resistance ring. Also you get bonus XCOM AP points from fighting off the one of the three "Chosen" assassins that sometimes appear during missions. The "giveresource AbilityPoint" give XCOM AP points that you can use to upgrade the abilities of any of the soldiers of the Reaper,Skimisher, or Templar Classes.