postgres: Fix pretty permalinks not being shown

templates: Add a link for the webmention endpoint

media: fix Axum behavior change with slashes in passed paths

configuration.nix: use NixOS option for ListenStream

media: fix improper path joining

Fix a few bugs

Add a NixOS test for receiving webmentions

Move NixOS tests to a separate folder to prevent clutter

dev.sh: small modifications

Log with tracing-tree AND json in debug builds

configuration.nix: bind on IPv6 localhost by default

This is so the Kittybox socket can actually listen on both IPv4 and IPv6.

Mount webmention handling routes and tasks

database: more documentation

webmentions: check webmentions and save them to the database

database: add "add_or_update_webmention" operation

This is an operation that atomically adds or updates a webmention cite
attached to a post. This is used so a database backend can optimize
for it (for example, using a transaction or shifting the JSON
modification operation to the database)

postgres: optimize fetching of non-feeds by forgoing a second query

Allow socket-activation for Kittybox

This complements passing sockets as FDs and graceful shutdown to allow
for zero-downtime restarts.

Allow loading TLS root certificates from file

Untested, but will be useful when testing Webmentions in the
end-to-end test.

Split Postgres schemas into two

Now the postgres schemas are completely independent of each
other. This took a while to figure out!

Move MentionType into util and fix bugs in -check-webmention app