Reload guard.yaml without losing the bounties

systemctl reload guard, guard reload or SIGHUP reads the configuration
again: a watch keeps its bounties and counts under the same name and
takes its new settings at once; its source starts again only if it
changed; watches gone stop, new ones start; a file with a mistake is
refused. The Housecarl connection, state, socket and log wait for a
restart, and guard reload says so.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -22,8 +22,14 @@ All notable changes to Guard are documented here. The format follows
   `postfix-sasl`, `dovecot`, `nginx-auth`, `housecarl-drops`
   (Housecarl's log of dropped packets, TCP only by default).
 - Commands: `guard run`, `check`, `config [--example]`, `presets`,
-  `test` (a watch's patterns over a log), `status` (through a local
-  socket), `bans`, `ban`, `unban`, `version`.
+  `test` (a watch's patterns over a log), `status` and `reload` (through
+  a local socket), `bans`, `ban`, `unban`, `version`.
+- Reloading: `systemctl reload guard`, `guard reload` or SIGHUP reads
+  guard.yaml again without losing the bounties. A watch keeps its
+  bounties under the same name and takes its new settings at once; its
+  source starts again only if it changed; watches gone stop, new ones
+  start. A file with a mistake is refused. The Housecarl connection,
+  state, socket and log wait for a restart (`guard reload` says so).
 - A Debian package with a sandboxed systemd unit, as the `guard` user in
   the `adm` and `systemd-journal` groups, published with each release to
   the Gitea Debian registry (`stable`, or `testing` for a release