The development server `amber serve` actually allows you to test this in
development as it has an option to fallback to serving specific page
instead of 404 when the path does not exist, exactly for this reason
(SPAs with HTML5 routes).
If you load the.js etc. from absolute paths, it should simply work. Then
you can use any routing library out there afaict (there are minimalistic
one, like leviroutes).
And of course, set up your actual deployment configuration to also serve
the proper .html file from nonexistent paths.
Herby