So you added 25% of the speed of the paddle to the ball. Godot give you paddle speed are did you have to track that yourself. So you change ball direction by taking the normal and adding 25 percent. I like the wall bounce damping.
Two things:
1. Could you ever move the paddle so fast that the ball misses it between frames or did capping the speed stop that? Did you use _physics_process() or _process()
2. I have been a programmer for almost 50 years, I still use ChatGPT, Grok, Calude.ai and another tool that I can get my hands on. In the arena of programming you use every tool you can get. It is no different than watching a tutorial on YouTube, buying some course, or reading it in a book which is what I did when I started programming 50 years ago. People have this stigma about AI. To me it is just a command line where you type in questions and it looks it up for you. Don't ever forget, you are a coder and all this code being spewed out by AI still needs to be checked.
I really liked your game, you are an excellent coder and designer. Keep it up, you never know you might have the next hit game in your head right now!!