fix: Enforce DNS Name matches Device Name for Forward Zone generation

sync.py

@@ -171,6 +171,31 @@ def generate_zone_file_fwd(ipam_data, plugin_records):
             short_name = dns_name.replace(f".{ZONE_NAME}", "")
             if short_name == "": short_name = "@"
 
+            # Check: DNS Name muss zum Device/VM Namen passen (wenn zugewiesen)
+            # Verhindert, dass externe IPs auf anderen Hosts (Split-Brain) hier landen.
+            assigned = ip.get('assigned_object')
+            if assigned:
+                device_name = None
+                if 'device' in assigned and assigned['device']:
+                    device_name = assigned['device']['name']
+                elif 'virtual_machine' in assigned and assigned['virtual_machine']:
+                    device_name = assigned['virtual_machine']['name']
+                
+                if device_name:
+                    # Case-Insensitive Vergleich
+                    d_norm = device_name.lower()
+                    s_norm = short_name.lower()
+                    
+                    # Erlaube Match mit Shortname ODER Full-FQDN als Devicename
+                    fqdn_norm = dns_name.lower().rstrip('.')
+                    
+                    if d_norm != s_norm and d_norm != fqdn_norm:
+                        # Ausnahme: Wenn der Shortname "device-name-irgendwas" ist? 
+                        # Nein, User will strikte Trennung.
+                        # Wir loggen das als Info, damit man es debuggen kann.
+                        # log(f"DEBUG: Skipping {dns_name} on device {device_name} (Mismatch)")
+                        continue
+
             if ":" in address:
                 rtype = "AAAA"
             else: