"I’m a junior in college studying math, physics, and CS. My goal is to become a world-class full-stack engineer who can build real-time systems, intelligent apps, and scalable infrastructure from scratch."

The systems like you describe aren't built by 1 person and for good reason. They are built by teams.

"What are the best projects, open-source repos, books, systems to study, or skills to master to reach the top 1% of engineers in 1 year?"

While a good goal to have, I think you should be focusing on soft skills (talking to people, communicating, translating business needs to code/plans) in addition to your engineering skills.

All of the best engineers that I know have all of these skills and even a passable amount will put you ahead of most engineers.

Learn to walk before you run and be humble. Have your goals, but I would assume you're in your late teens or early 20s. Your goals may not align to Real Life, and that's OK.

Don't waste time on kicking yourself for not being some "superstar" developer. There are a lot of not-superstar developers who make a huge difference in computing.

Most of the NT kernel team is unknown, by and large. But they had an oversized impact to the computing world. Same goes to Linux kernel devs.

There is this thing we might refer to as “the burn.” You know, like “burn your ass to get it done.” Only for knowledge workers, it is an ember in the mind that goes and goes and goes and goes.

Learn to fan that flame without the burn out.

That is the secret of the way.

Burn your ass until your mind incinerates self doubt. You will learn it is faster to try some things than wonder if they might work.

Burn your ass until those reasons why not are forgotten, or are repulsive.

Burn your ass until all of those things others say cannot be done without a team are done out of boredom waiting for others to get on the same page.

There is no book, only determination, and outcome.

Some day you will realize everyone else is 90% lazy and you will adjust your work life balance in accordance.