feat: host-level watch flag suppresses notifications; filter dashboard/overview by owner/manager; add ZFS monitor plugin

- watch: true (default) per host; watch: false suppresses all notifications
  for that host in udp.py and threshold.py
- Live Dashboard and Host Overview now show only hosts where the logged-in
  user is owner or manager (admins see all); WebSocket broadcasts filtered
  per-connection by the same rule
- Add hbd/client/plugins/zfs_monitor.py: collects per-pool health, capacity,
  fragmentation, dedup ratio, and cumulative I/O ops/bandwidth via zpool(8)

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

hbd/server/hbdclass.py

@@ -286,7 +286,7 @@ class Host:
             Host.hosts[name] = self
         self.num = num
         self.dyn = False
-        self.watched = False
+        self.watched = True
         self.upcount = 0
         self.interval = 0
         self.doesack = -1
@@ -304,6 +304,7 @@ class Host:
 
     def statedict(self):
         d = {}
+        d["raw_name"] = self.name
         d["name"] = self.name
         if self.dyn:
             d["name"] += "*"