this takes what i love about 'next/meta' (originally imported via my
'next-metadata' port) and consolidates it into a simple 250 line
library. instead of supporting all meta tags under the sun, only the
most essential ones are exposed. less common meta tags can be added with
JSX under the 'extra' field.
a common problem i had with next-metadata was that open graph embeds
copied a lot of data from the main meta tags. to solve this, a highly
opiniated 'embed' option exists, which simply passing '{}' will trigger
the default behavior of copying the meta title, description, and
canonical url into the open graph meta tags.
the asset system is reworked to support "dynamic" entries, where each
entry is a separate file on disk containing the latest generation's
headers+raw+gzip+zstd. when calling view.regenerate, it will look for
pages that had "export const regenerate" during generation, and render
those pages using the view system, but then store the results as assets
instead of sending as a response.
pages configured as regenerable are also bundled as views, using the
non-aliasing key "page:${page.id}". this cannot alias because file
paths may not contain a colon.
"server side rendering" is a misleading term since it implies there is a
server. that isn't neccecarily the case here, since it supports running
in the browser. I think "clover engine" is cute, short for "clover html
rendering engine". Instead of "server side rendering", it's just rendering.
This commit makes things a lot more concise, such as `ssr.ssrAsync`
being renamed to `render.async` to play nicely with namespaced imports.
`getCurrentRender` and `setCurrentRender` are just `current` and
`setCurrent`, and the addon interface has been redesigned to force
symbols with a wrapping helper.
