If you - or others here - are interested I can spend some time to clean-up my own "boilerplate" a bit.

It's using Golang + Chi + Templ, uses SQLite as its database and has a multi-tenant-multi-db setup by default (i.e. 1 master database for user/tenant management, and "stem-data", 1 sqlite database per tenant), and uses passkeys for authentication. I'm using some HTMX + Hyperscript + a really small amount of plain-js for passkeys in the apps themselves.

I reckon that switching out Chi for Fiber - for the boilerplate only - would take about 90 minutes.

Edit: Forgot to include TailwindCSS. So for completeness sake.