printers: add format=text to install-list + pc-default; vendor via model

The Inno printer installers hand-parsed JSON in Pascal (brittle brace-counting).
Add ?format=text to install-list (one printer per line, pipe-delimited:
printerid|windowsname|vendorname|modelnumber|hostname|ipaddress|mapx|mapy) and
to pc-default (printerid|windowsname), so the installer side is a split() with
no JSON parser. The web map keeps the default JSON.

Also resolve install-list's vendorname via the model (as the batch already does),
since the import sets the model, not the printer's direct vendorid - otherwise
the installers' HP/Xerox/Brother filter drops every prod printer.

plugins/printers/api/asset_routes.py

@@ -343,7 +343,7 @@ def printer_install_list():
             'sharename': printer.sharename,
             'hostname': printer.hostname,
             'ipaddress': ipaddress,
-            'vendorname': data.get('vendorname'),
+            'vendorname': _printer_vendor(printer),
             'modelnumber': data.get('modelname'),
             'installpath': printer.installpath,
             'iscsf': printer.iscsf,
@@ -352,6 +352,15 @@ def printer_install_list():
             'mapy': asset.mapy,
         })
 
+    # A pipe-delimited text variant for the Inno installers: one printer per
+    # line, fixed field order, so the Pascal side is a split() instead of a
+    # hand-rolled JSON parser. The web map uses the default JSON.
+    if request.args.get('format') == 'text':
+        fields = ('printerid', 'windowsname', 'vendorname', 'modelnumber',
+                  'hostname', 'ipaddress', 'mapx', 'mapy')
+        lines = [_text_line(row, fields) for row in rows]
+        return Response('\n'.join(lines), mimetype='text/plain')
+
     return success_response(rows)
 
 
@@ -378,6 +387,17 @@ def _batch_base_url():
     return 'https://%s%s' % (host, root)
 
 
+def _text_line(row, fields):
+    """One pipe-delimited line for the installer text format. None -> empty;
+    any pipe/newline in a value is neutralized so the field count stays fixed."""
+    parts = []
+    for key in fields:
+        value = row.get(key)
+        text = '' if value is None else str(value)
+        parts.append(text.replace('|', ' ').replace('\r', ' ').replace('\n', ' '))
+    return '|'.join(parts)
+
+
 def _printer_vendor(printer):
     """Vendor name for install grouping. The legacy import sets the printer's
     model but not its direct vendorid, so resolve via the model's vendor (as the
@@ -560,14 +580,21 @@ def pc_default_printer():
     Returns {printerid, windowsname}, or {} when the machine is unknown or has
     no active default printer set.
     """
+    as_text = request.args.get('format') == 'text'
+
+    def _empty():
+        # Text variant returns an empty body (no default) so the installer's
+        # split yields nothing; JSON keeps the {} contract.
+        return Response('', mimetype='text/plain') if as_text else success_response({})
+
     machine = (request.args.get('machine') or '').strip()
     if not machine:
-        return success_response({})
+        return _empty()
 
     pc = Asset.query.filter_by(assetnumber=machine, isactive=True).first()
     dp_type = RelationshipType.query.filter_by(relationshiptype='defaultprinter').first()
     if not pc or not dp_type:
-        return success_response({})
+        return _empty()
 
     rel = AssetRelationship.query.filter_by(
         sourceassetid=pc.assetid,
@@ -575,14 +602,21 @@ def pc_default_printer():
         isactive=True,
     ).first()
     if not rel:
-        return success_response({})
+        return _empty()
 
     printer = db.session.query(Printer).join(Asset).filter(
         Printer.assetid == rel.targetassetid,
         Asset.isactive == True,
     ).first()
     if not printer:
-        return success_response({})
+        return _empty()
+
+    if as_text:
+        return Response(
+            _text_line({'printerid': printer.printerid,
+                        'windowsname': printer.windowsname},
+                       ('printerid', 'windowsname')),
+            mimetype='text/plain')
 
     return success_response({
         'printerid': printer.printerid,