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.

tests/test_plugins/test_printer_install_list.py

@@ -38,6 +38,54 @@ def test_install_list_returns_network_printer_with_map(client, db, auth_headers,
     assert row['mapx'] == 120 and row['mapy'] == 240
 
 
+def test_install_list_vendorname_resolves_via_model(client, db, auth_headers,
+                                                    printer_assettype):
+    """vendorname falls back to the model's vendor when the printer has no
+    direct vendorid (the import sets the model, not the printer's vendor). The
+    Inno installer filters on this, so it must not be null on real data."""
+    from shopdb.core.models import Vendor, Model
+
+    hp = Vendor(vendor='HP')
+    db.session.add(hp)
+    db.session.commit()
+    model = Model(modelnumber='LaserJet M607', vendorid=hp.vendorid)
+    db.session.add(model)
+    db.session.commit()
+
+    client.post('/api/printers', json={
+        'assetnumber': 'CSF09-2022-HP', 'hostname': 'wjprn09',
+        'modelnumberid': model.modelnumberid,
+    }, headers=auth_headers)
+
+    resp = client.get('/api/printers/install-list', headers=auth_headers)
+    row = next((r for r in resp.get_json()['data']
+                if r['machinenumber'] == 'CSF09-2022-HP'), None)
+    assert row is not None
+    assert row['vendorname'] == 'HP'
+
+
+def test_install_list_text_format(client, db, auth_headers, printer_assettype):
+    """format=text returns one pipe-delimited line per printer (fixed field
+    order) so the Inno installers split() instead of parsing JSON."""
+    client.post('/api/printers', json={
+        'assetnumber': 'CSF01-HP', 'windowsname': 'CSF01-HP', 'hostname': 'wjprn01',
+        'mapx': 120, 'mapy': 240,
+    }, headers=auth_headers)
+
+    resp = client.get('/api/printers/install-list?format=text', headers=auth_headers)
+    assert resp.status_code == 200
+    assert resp.mimetype == 'text/plain'
+    line = next((l for l in resp.get_data(as_text=True).splitlines()
+                 if 'CSF01-HP' in l), None)
+    assert line is not None
+    cols = line.split('|')
+    # printerid|windowsname|vendorname|modelnumber|hostname|ipaddress|mapx|mapy
+    assert len(cols) == 8
+    assert cols[1] == 'CSF01-HP'      # windowsname (falls back to assetnumber name)
+    assert cols[4] == 'wjprn01'       # hostname
+    assert cols[6] == '120' and cols[7] == '240'
+
+
 def test_install_list_excludes_usb_only_printer(client, db, auth_headers,
                                                 printer_assettype):
     """A printer with no hostname and no network IP is excluded."""