Whoa. Take A Deep breath.
Speaking as a director-level leader of a shadow IT group who has (pardon my French) been through some shit, the situation isn't as bad as it looks on the surface....
Some key points:
- yes. You've got a cluster fuck in progress; K seems to be lacking in IT mgmt skills.
- regarding reviews, raises, and promotions they can do more or less whatever they want with those and nothing counts until the ink is dry. Nor will anyone who matters give two shits about them 90 days later. None of my big $ moves ever lined up with any review (actually, most of the time it was exactly opposite).
- The more pertinent question is "will I be fired" over this? Which would be silly if the facts are as you say. You are one of the remaining few who understands how the app is supposed to work.
In the long run, you know how the system works and she does not. I've played this game before several times and wind up walking my tormentor out the door.
Suggestion: mentally write off the promotion and ignore your review, dismiss all short term noise; focus on things which drive where you will be 12M-24M out. (This is also why I have never protested a review in the past 15 years; nobody gives a shit if you survive).
Fun games to play:
1) Inform C that you don't have enough access to what is going on in K's process, due to being excluded from the team lead meetings. Point to this as a source of delays and "confusion". Do so in writing.
2) Get K to put down specs; go ask clarifying questions with appropriate next level mgmt on copy. Gently highlight gaps.
3) Ideal time to get creative in how you develop / document solutions on the front end; I would give as little detail as possible to make it harder to fire me.
4) Call a meeting of your own, that overlaps the purpose of the meeting she excluded you from. It's agenda should be something like requirements validation or solution design. Be nice but indicate you need it to accomplish your goals.
What you're setting up here is a slow boiling cauldron of incompetence charges again K and yourself as a trusted "competent" source in the app and underlying technology.
Move SLOWLY and GENTLY in laying this groundwork; soft innocent questions are best. Be like water...drip drip drip. Slowly wearing away at her credibility and building your own. Maintain emotional control and calm when she lashes out (she will).
Look for a new job, of course. This crap may be more than you want to deal with and that's ok. But there are ways of fighting back against bullies like this....