tardypad.me: fix certificates renewal
system-config: Remove warning message about manual updates on upgrade

This is not needed since the modified file is not going to be
overwritten by apk. An .apk-new file will be created to be handled later
on with update-conf.
builds: delete symlink to downloaded snapshot at end of build

To declutter the repository from invalid symlinks on the host.
The snapshots are kept in the SRCDEST dir for now.
system-config: minor style changes in nftables rules

- go to new lines for each rule
- use variables
system-config: update nftables rules to allow forwarding WireGuard traffic
system-config: enable IP forwarding

For usage with WireGuard
system-config: add nftables with basic firewall rules

Many coming from default package config
system-config: add basic WireGuard configuration
system-config: change radicale collection directory

Put it in home folder so that it's possible to upload it from the backup
during the setup process.
setup: pkgs directory needs to be prepared before backup upload

See related commit ee07472b8428b84b188e19199545dbfe9bf9a0eb
The directory is also created by the package but this one needs to be
uploaded first
setup: system-config is the only package needed to be installed
system-config: make jargon-gemini and tardypad.me dependencies

So that system-config contains the full list of explicitly installed
packages like we do on Arch.
jargon-gemini: do not fail install if post-install commands fail

Somehow it fails when installed as a dependency in the container during
a build process
tardypad.me: only fetch certificates and restart when being installed on chestnut

Both would fail when testing the install on the container
utilities: allow installation of local packages in container

Will be needed during build for local dependencies
bin: fix build index

The index contains all the packages present in the directory so we
shouldn't do the build on an empty folder, otherwise the index would
contain only one item.

This is different than the build "index" on Arch where a single item
could be added to the existing db.
utilities: add more config for rsync usage to chestnut within container
utilities: share SSH agent between host and container
tardypad.me: bump version to build carl subdomain
system-config: add radicale package with basic config

Only enable authentication via reverse proxy