1. No one is going to advocate for your interests other than you;
2. How hard you work doesn't matter. It may even be detrimental. What matters is how your work is perceived. Hopefully that correlates with adding value to the business (and you should be able to quantify that) but that's not necessarily true; and
3. Listen to the money. Words cost nothing.
Big companies are political. You will often find you get the best results merely ingratiating yourself with various key people and talking a lot about how hard your job is and how amazing the things you've done are.
Even bringing up problems to your manager can hurt you. Often you won't be rewarded for foreseeing a problem. You'll be punished for being negative. Your manager may simply not be talking to you because you (in their mind) "create" problems.
Let me put another way: if you anticipate a problem and fixes it before it becomes a problem there's a good chance you'll get absolutely zero credit for it. But if things blow up spectacularly and you come in and save the day? Well, you're hte hero.
As for your manager bringing in a friend. It might be a friend. More likely (IME) is it's someone your manager has simply decided they like. They may like them because the new engineer doesn't "create" problems. It could be as simple as some common background (eg same college) or it could just be vibes.
As for being told you are the "best engineer", words cost nothing. If that praise doesn't translate into some kind of reward (eg promotion or direct compensation) it means exactly nothing. You will find a lot of managers wil learn who can be assuaged with words.
Listen to the money.
As for getting the "cold shoulder" treatment, it could be that the rest of your team can see which way the wind is blowing and don't want to get on your manager's bad side. A lot of work life is simply currying favor. But you need to take a good, hard look at how you conduct yourself at work. Why? Because it could be that they just don't like you.
The reasons for this can be (and often are) completely superficial. Maybe they view you as negative. Maybe you don't know how to carry a conversation. Maybe you don't ask them about themselves. Maybe you one-up them. Who knows?
Engineers tend to be more introverted and less socially skilled on the whole than the general population (IME). Learning social skills and learning how to be liked will take you so far in life. I cannot overstate this. Being liked can be the difference between "failing to deliver" and "trying hard against impossible odds with learnings that we take to future projects" for the exact same set of facts.