Change visible name format to QRS-{site}MB-{screen}

New format: QRS- + first 4 chars + MB- + remainder
Example: AMS-COF1 -> QRS-AMS-MB-COF1

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/zabbix.py

@@ -3,7 +3,7 @@ Zabbix API client for automatic host management.
 
 Each Yodeck player becomes a Zabbix host with:
   - hostname  : yodeck-<yodeck_id>
-  - visible name: "QRS-" + the Yodeck player's display name (e.g. QRS-AMS-COF1)
+  - visible name: "QRS-" + first 4 chars + "MB-" + remainder (e.g. AMS-COF1 -> QRS-AMS-MB-COF1)
   - SNMP v2c interface pointing to this app (APP_HOST:161)
   - Four SNMP items: online, last_seen, updating, registered
 """
@@ -172,7 +172,7 @@ def sync_to_zabbix(players, add_log_fn):
         for player in players:
             yid      = player['id']
             hostname = f"yodeck-{yid}"
-            visible  = f"QRS-{player['name']}"
+            visible  = f"QRS-{player['name'][:4]}MB-{player['name'][4:]}"
 
             if hostname not in existing:
                 hostid = zbx.create_host(hostname, visible, groupid)