I don’t think Trump has the sophistication to be a Russian agent. The sad truth is just that he’s wannabe dictator who admires Putin as a role model. Russia is as surprised at their luck as anyone else.
"Russian agent" != trusted collaborator. It means they can use you. He's perfectly predictable/controllable using just flattery and greed, which petro terrorist states like Russia can utilize quite generously.
Trump is an open book, he says he wants the killing to stop and to save money, but saving lives is more important. Many people also believe this, and that failed negotiations and bad relations between NATO and Russia lead to this.
It’s not pro-Russian to want a conflict to end, it’s terrible to think that not wanting people to continue to die is considered bad if it happens to include people of a specific nation who have little control over their leadership currently.
Zelensky would really like this war to end (he said so in the meeting), but he also realizes that Putin can't be trusted - give him an inch and he'll take a mile. The kind of "peace" that Trump wants is the "peace in our times" of Chamberlain or the "peace" of the Molotov-Ribbentrop pact - the kind of "peace" that ultimately leads to more war.