blitz v2 follow-on issues

[Vandivier]

#189 incurred some tech debt which isn't necessarily high priority. probable seo and performance improvements from solving these, i'm not immediately sure of magnitudes. here are the tasks:

1. audit cases of "use client" and basically use it less often
2. ensure metadata is properly exported and proper SEO is occurring

[Vandivier]

fix prettier integration for local dev

[Vandivier]

use new layout, similar to create-next-app layout file, not old Layout.tsx

[Vandivier]

also, about typed routes:
blitz-js/blitz#4306

[Vandivier]

import { useRouter } from "next/compat/router"

the place we use that (within layout file) needs to be updated so that we don't make all pages use client

we can accomplish canonical identification at build time by other means, such as by exporting SEO meta per-page

[Vandivier]

1. reconcile duplicate layout.tsx files and other duplicate components
2. less "use client"
3. don't import { useRouter } from "next/compat/router"
4. use new site meta / page meta pattern instead of Head tag in layout file(s)
5. make sure sitemap works

[Vandivier]

see: https://blitzjs.com/docs/upgrading-from-framework

[Vandivier]

there's some flash of undesirable content on /signup and maybe some other pages

[Vandivier]

"Loading..." flash is ick
We shouldn't need "use client" on every page due to menu login state detection
layout can be updated not to useRouter and to require slug

[Vandivier]

closing bc we will just use t3