Initial import: nasmon health monitor, split out of home_nas

Go service (nasmon/) plus nfpm packaging (packaging/), carried over from
the home_nas monorepo. Adds rpm packaging alongside the existing deb
build (Fedora/RHEL/Rocky dependency names via nfpm overrides, per-format
systemd unit path, dpkg+rpm-compatible maintainer scripts) and a Gitea
Actions workflow that builds both formats on every push.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

packaging/wsdd.service

@@ -0,0 +1,16 @@
+# Installed by nasmon: the Ubuntu wsdd package ships no unit file.
+# wsdd answers WS-Discovery so the NAS shows up under "Network" in Windows Explorer.
+[Unit]
+Description=Web Services Dynamic Discovery host daemon
+After=network-online.target
+Wants=network-online.target
+ConditionPathExists=/usr/bin/wsdd
+
+[Service]
+ExecStart=/usr/bin/wsdd --shortlog
+DynamicUser=yes
+Restart=on-failure
+RestartSec=10s
+
+[Install]
+WantedBy=multi-user.target