I hear ya. I've always found plugins for this kind of stuff tend to be overkill. Why? Because it's more about the pattern than anything.

e.g., I tend to follow this patter in dancer2 apps for authentication:

• unauthenticated request handler to process login form (or HMAC auth form API)
• check auth credentials somehow
• on success, store session info on $USER
• on fail, throw a 403 or something
• all other endpoint handlers are authenticated by an assertion that the session $USER is valid; failure redirects or throws 403 as appropriate

So there are keywords that do this already: post, session, and send_error.

So what would actually be useful, and I've thought about this, is a repository of single page "apps" that do things like implement authentication (like the old PHPlib used to provide) or implement an example of doing HMAC authentication for API handling, etc. I good one also would be how to handle an eBay IPN (payment notification) which turns out to be trivial in dancer2/mojo - everyone likes getting paid, here's how! xD