Hi, I am preparing to release my own solitaire game here because steam denied it due to the use of AI generated art on the card decks, so I thought I would go and check out some of the competition here. Your game stands out among the others due to its polish. Nice Job!
A couple suggestions I have would be that when the stock is empty you should probably turn off the card back that represents it. It is confusing to see a "card" left when there really aren't any. a couple of quality of life improvements could include flipping the face down cards face up once they are uncovered in the tableau. Similarly, any card in the tableau ranked less than three below the lowest card in the foundations can safely be thrown to the foundations. It makes it easier to play, prevents the player from missing a move they should make. Most importantly, it will automatically finish out the game for you automatically once all the cards left are faced up and built in rank ordered piles.
Any way, great job. You should be proud! 8^)