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)

displaysubnets.asp

@@ -54,7 +54,7 @@
                  			 </thead>
                   		<tbody>
                     			<tr>
-		      				<form method="post" action="./addsubnetbackend_direct.asp">
+		      				<form method="post" action="./addsubnetbackenddirect.asp">
                       				<th scope="row"><input class="form-control" type="text" name="vlan" size="4"></th>
                       					<td><select name="subnettypeid"  class="btn btn-light px-3">
 <%
@@ -94,7 +94,7 @@
 <BR>
 </div>
 		</div>
-              <h5 class="card-title"><a href="./network_map.asp" target="_blank"><i class='zmdi zmdi-map' title='Show Network Infrastructure Map'></i></a>&nbsp&nbsp;Subnet Details</h5>
+              <h5 class="card-title"><a href="./networkmap.asp" target="_blank"><i class='zmdi zmdi-map' title='Show Network Infrastructure Map'></i></a>&nbsp&nbsp;Subnet Details</h5>
 			  <div class="table-responsive">
                <table class="table table-hover">
                   <thead>