great work! Now it's time to learn about heat shrink tubes :)

I think somebody else reccomended some, but they have built in solder, I like these, and have been using them for like a year: https://www.amazon.com/560PCS-Heat-Shrink-Tubing-Eventronic/dp/B072PCQ2LW/ref=sr_1_3?keywords=heat+shrink+assortment&qid=1642023397&sr=8-3

The 'trick' is to put all of them on the wire ahead of time, including the outer-most sleeve, then it all goes back together with barely a bump where you spliced it :)