It's a shitty move, but ultimately, in between the bullshit narrative, they also did the thing - not you - so the promotion rightfully belongs to them.
Execution trumps ideas, impact trumps raw effort, and such. Isn't this the entrepreneurial narrative?
Sure thats obviously how it works today.
Now what do I do next time someone comes and asks how to do something?
Of course you tell them, because you're nice person, and not jealous of someone else succeeding in a thing you aren't even pursuing? You wouldn't want to act like "the dog in the manger" from childhood stories.
LOL I have no idea about the dog in the manger. You have my full attention, please tell me the story.
I bet you do, you probably don't recognize it because it has different names in different places (for me, it's known as "pies ogrodnika" - "the dog of the gardener"). It's an old tale.
https://en.wikipedia.org/wiki/The_Dog_in_the_Manger