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)

addmodel.asp

@@ -40,7 +40,7 @@
                 </a>
               </div>
 
-              <form method="post" action="./savemodel_direct.asp" id="modelForm">
+              <form method="post" action="./savemodeldirect.asp" id="modelForm">
                 <div class="form-group">
                   <label for="modelnumber">Model Number <span class="text-danger">*</span></label>
                   <input type="text" class="form-control" id="modelnumber" name="modelnumber"