3.2 to 4.0, in a year: would this push look better or worse than a kid who has just gotten 4.0s since middle school?

Since all applications are individually evaluated on a holistic basis, it's hard to tell if your admissions reader would find your narrative more impressive than someone that consistently had straight As. My personal feeling is that while you are making up for lost ground, you will never have a 4.0 cumulative GPA, and but you can feel good about doing your best and having a renewed purpose with your schoolwork and performance. I don't think anyone would be responsible for telling you that if you kick butt the 2nd half of high it fully exonerates you and overcompensates you so you look better than the kids that have been grinding and kicking butt all 4 years of High School. That's not going to happen. What is most likely evaluation is that AOs (Admissions Officers) who read your file and look at your transcript will see an upward trend in grades and test scores and see your potential. I think that if you are in a maybe position with 2 other applicants who have similar stats, someone will advocate for you showing initiative and ending on a high note. But those that have unweighted 4.0s still matter.

My advice is to continue improving your grades and strive to get that 4.0 you are talking about. And if you achieve a 4.0 next semester, try to keep your 4.0 for 11th and 12th grade. The next thing is a bit more tricky, I would opt for the most challenging courses offered by your HS, so all the APs ones for 11th and 12th grade. Course rigor is really important. If you graduate with a 3.75 unweighted GPA but have taken 7 AP classes and scored 4s and 5s on the AP tests, that's more impressive than someone who has a 4.0 that took the easy way out and maybe only has 1 AP class. and a 3 on the test.

I'm not so sure about the NAIL TECH license, that seems diametrically in the opposite direction of what an Ivy League school wants to see on your application file. It would make more sense to use the time and effort to volunteer in your community or hold a valuable leadership position in your high schools, such as team captain of a Varsity Sport, editor of the newspaper, President of Decca or Model UN, or some student government officer. ECs matter a lot with Ivy league schools so get cranking and involved in more community activities or start your own club or non-profit.

The last thing is that while 95% percentile is good for PSAT, you really need a 99% percentile score to get to be a Semi-finalist or better. So keep up the PSAT grind and take a lot of practice tests. If you can't get a 99% score on a practice test, move onto the SAT, and aim for a 99% on the SAT. Collegeboard will allow you to use your SAT score in lieu of your PSAT to qualify for Merit Scholarships but you have to submit your SAT score before you take your 11th-grade PSAT test next year. It's a wise fallback because if you have a 99% SAT score, you can use that to apply to any college.

Good luck.