Start treating your bedroom door like a real "front door."
If she knocked on the door of your apartment, you might say (if she could hear you), "coming!"
Or, you wouldn't say anything, and you'd just get up, go over, and open the door, right?
So do that. Don't say "yeah?" when she wiggles the doorknob. That's the routine for teenagers, and it's time for you to start setting the stage for adult interaction. So start modeling it.
Don't say "what for?" when she says "open the door." Again, that's teenager routine.
In fact, don't ever let it get that far.
She knocks; you get up and go answer. You stand in the doorway, and say, "Oh, hello!" And then she can either ask you whatever it was she asked you face-to-face, or you can decide you want to say, "Oh, come in, Mom," and step back to allow her in, and welcome her exactly the way you would if you were living in a separate apartment and she dropped by.
For one thing, if it's clear that she completely interrupts you every single time she knocks at your door, she might interrupt you less often.