fix NaN 0 bug in decomp serice, made trig rigorous in latex gen

[CaptainChicky]

Hey, nice refactor!

Anyway here are the same 2 bugs from 2023 that still need fixing 🥀
i beg, please fix these they are actually bugging me so much @enjeck

1. 0 decomposition results in nan and undefined: NaN appearing in expressions for integer zero #21 Fix issue #21 #22 this is fixed in decomposition service b y excluding 0
2. cosine and sine are not rigorous 🥀💔 you are making an equation, not a computable expression, please fix this, you dont have to copy my limit values but at least add a limit that you like by editing my PR or something pls

i discarded my original PR #23 and had to go through all your new refactored code for this xd

[enjeck]

Thanks! It didn't work fully for me, and I couldn't push to your branch, so I incorporated your changes into 8dddcb7. Appreciate the help

[CaptainChicky]

tysm 💖