in reply to
Designing a user interface for a CGI application.
The question, as discussed on SO, is a bit overbroad.
Web dev work can be like carpentry. Anyone can bang together a few pieces of knotty pine with whatever nails seem sensible and maybe have it stand but only a real carpenter knows the tools, techniques, and materials. How do you build a home entertainment center… just in general? Hard to answer in general. Long and very detailed to answer as "this is what I would do."
A little CGI with a dispatch table is probably what I would do here if it's a one-off; search around for "dispatch table" and "CGI." Or even a naked plack script with a handful of subs as the dispatch table; it's too bare metal for most stuff but it can be fun and edifying for short-lived projects. A Mojolicious::Lite app is what I'd do if I'm being a bit more serious or want it to be RESTy and respond to anything but a few few plain HTTP requests. SQLite sounds like a perfect choice for it. DBIx::Class makes that stuff easy (after you get over the learning curve) but it is on the slower side so a persistent app (i.e., not plain CGI but PSGI through an app server) would be helpful.
Don't worry about too minimalistic. Simple UI that affords what the user wants to do is good UI. You can tart it up with Ajax to make it slicker and sometimes a lot faster. But that's a whole lot of off topic.