There's an expression I can't remember about someone else taking over a project at the very end, and taking credit for it - something like taking it the last mile, taking it in for the touchdown...
I.e. I don't want her coming in on the final minute and bringing it in for the touchdown/homerun/taking it the last mile.
There's the expression steal someone's thunder:
[Merriam-Webster]
: to prevent someone from having success or getting attention, praise, etc., by doing or saying whatever that person was planning to do or say
// I didn't mean to steal your thunder, but I just had to tell your mom about your promotion.
While it's a broader term, it does also apply to the specific situation you describe.
Somebody could come into a project after all the hard work has been done, present the result to management, and reap the reward for having accomplished the task:
She came in after I'd done all the hard work and stole my thunder.
