Additionally, should we more-strongly recommend that the script be included in templates?

I'm not sure. Probably not immediately. I think it'd be a good idea to dogfood it for a while and then maybe then if it proves to be a good idea we can more strongly recommend it to users.

It's also lacking a good Windows equivalent, and idk how much of an issue that'll be for customers.

It's also lacking a good Windows equivalent, and idk how much of an issue that'll be for customers.

Many of our users use Windows or macOS devices. So this will be an issue.
We could provide a Windows equivalent install script, too.

iwr https://coder.example.com/install.ps1 | iex

Also, let's include these as part of CLI suggestions when we detect a version mismatch instead of documenting this in docs. E.g.,

version mismatch: client v2.17.0+5a6d23a, server v2.18.2-devel+3a81aac31
- download the server version with: 'curl -L https://coder.com/install.sh | sh -s -- --version 2.18.2-devel'
+ Download the server version with: 'curl -L https://dev.coder.com/install.sh | sh'

And best if we can automagically do that,

version mismatch: client v2.17.0+5a6d23a, server v2.18.2-devel+3a81aac31
- download the server version with: 'curl -L https://coder.com/install.sh | sh -s -- --version 2.18.2-devel'
+ Download the matching version from the server (y/n): y

providing a windows equivalent and changing the cli are waaaay out of scope for this PR. I'm relatively comfortable writing bash scripts, but powershell is a whole different beast.