Shares of other services and RepoISO integration

- include SMB drop-ins from /etc/samba/smb.conf.d into the generated smb.conf
- keep smbd/nfs-server running while other services (/etc/exports.d, drop-ins) share,
  instead of disabling them when nasmon has no shares of its own
- list those shares read-only on /shares
- settings: RepoISO URL; poll its /api/integration/status, dashboard card, menu link,
  alerts for portal down, stale worker, failed jobs, unmounted publications

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

packaging/README.md

@@ -47,3 +47,29 @@ Alerts: the × on an open alert acknowledges it (hidden and not mailed until the
 problem changes or clears); the × on a resolved alert removes it from the log.
 Resolved alerts older than 7 days are hidden by default, older than 90 days
 deleted.
+
+## Shares of other services
+
+Other software on the host can publish shares without fighting over the
+config files nasmon owns:
+
+* SMB: drop a fragment into /etc/samba/smb.conf.d/<name>.conf. nasmon appends
+  "include = <file>" for every *.conf there to the smb.conf it generates.
+* NFS: write /etc/exports.d/<name>.exports.
+
+nasmon lists these shares read-only on /shares and keeps smbd / nfs-server
+enabled while any of them exist, even with no nasmon shares (previously it
+disabled the daemons and took such shares down). When SMB is switched off in
+nasmon, only nasmon's own shares are removed.
+
+## RepoISO integration
+
+Settings → Integrations → RepoISO URL (e.g. http://127.0.0.1). nasmon then
+polls <url>/api/integration/status every minute and
+
+* shows a RepoISO card on the dashboard (images, publications, jobs, Proxmox
+  exports, worker heartbeat) and a "RepoISO" menu link;
+* alerts: crit when the portal does not respond, warn when its worker has no
+  heartbeat, when jobs failed in the last 24 h or publications are not mounted.
+
+The status endpoint answers only on loopback, so use the local address.