Migration of Vue2 web to Vue3 plus modernization

I have an existing website running at https://www.eduquant.cz/ .

This website was created a while ago, and its main problems are:
- Uses old Vue2
- Contains a weird, tweaked copy of Bootstrap v4.0.0 (from the original developer)
- References old versions of various libraries, some of which have been dead for multiple years
- Has some SEO-related suboptimalities

The deliverables of this project are:
- Upgrade to Vue3
- Upgrade to relevant newer libraries (some may be dropped as no longer necessary)
- Migration to Bootstrap 5 (or whatever the newest version is), including removal of most of the files from src/assets/scss (mostly exact copies of Bootstrap v4.0.0 files) and replacing them with only modifications to the default Bootstrap 5 behaviour (i.e. custom variables, other custom code, etc.)
- Adding some SEO optimizations that will be further specified later (e.g. including meta description to individual pages, automatic generation of sitemap and robots.txt).

A testing environment has been created on an AWS EC2 instance where full access will be granted. Once the site looks the same as the original one, the result will be deployed to the production site.

The intention is to keep the site looking the same; however, any improvement suggestions will be considered, and extra workload may be granted if the change makes sense.