iPhone 15 case slim version

Updated a 1.2mm thickness version, better print with PETG更新了一个1.2mm厚度的版本，最好使用 PETG 打印 I found that the phone cases available on the website were too thick, bulky, and lacked bottom protection. Additionally, due to issues with the opening shape and interlayer adhesion of the material, they tend to crack easily after inserting the phone.Therefore, after a whole day of modifications, trials, and test prints, I have achieved the best version so far. I have made the following improvements:Reduced the