Standardize ASP filenames: remove underscores

Renamed 45 ASP files to follow lowercase concatenated naming convention:
- Direct handlers: save_machine_direct.asp -> savemachinedirect.asp
- USB files: checkin_usb.asp -> checkinusb.asp
- API files: api_usb.asp -> apiusb.asp
- Map files: network_map.asp -> networkmap.asp
- Printer files: printer_lookup.asp -> printerlookup.asp

Also:
- Updated 84+ internal references across all ASP and JS files
- Deleted 6 test/duplicate files (editmacine.asp, test_*.asp)
- Updated production migration guide with filename changes
- Added rename scripts for Linux (bash) and Windows (PowerShell)

includes/leftsidebar.asp

@@ -83,7 +83,7 @@ End If
 
       <li class="sidebar-header">Admin</li>
       <li><a href="./displaysubnets.asp"><i class="zmdi zmdi-network text-danger"></i><span>Network</span></a></li>
-      <li><a href="./network_devices.asp"><i class="zmdi zmdi-device-hub text-info"></i><span>Network Devices</span></a></li>
+      <li><a href="./networkdevices.asp"><i class="zmdi zmdi-device-hub text-info"></i><span>Network Devices</span></a></li>
       <li><a href="./displaypcs.asp"><i class="zmdi zmdi-desktop-windows text-primary"></i><span>PC Admin</span></a></li>
       <li><a href="./displayusb.asp"><i class="zmdi zmdi-usb text-purple"></i><span>USB Devices</span></a></li>
       <li><a href="./displaynotifications.asp"><i class="zmdi zmdi zmdi-notifications-none text-success"></i><span>Notifications</span></a></li>

includes/zabbix_cached.asp

@@ -38,7 +38,7 @@ Function GetPrinterDataCached(hostIP)
             Dim http
             Set http = Server.CreateObject("MSXML2.ServerXMLHTTP.6.0")
             ' True = async (doesn't block user)
-            http.Open "GET", "http://localhost/refresh_zabbix_cache.asp?ip=" & Server.URLEncode(hostIP), True
+            http.Open "GET", "http://localhost/refreshzabbixcache.asp?ip=" & Server.URLEncode(hostIP), True
             http.Send
             Set http = Nothing
             On Error Goto 0