PC set-up: one line per PC (/setup/<name>.ps1), the admin laptop always let in, and the admin check no longer breaks the script

- the inserted administrator check split the header comment, leaving '} for ... run ONCE' as code: WS and SC
  join.ps1 failed to parse (Windows' parser: Missing opening '(' after keyword 'for'); now after the whole line
- site.admin_ips / admin_keys (laptop 10.6.7.38, fixed in UniFi) go into every PC script's firewall rule and key
  files, and into the Mac join line, so running a set-up again never shuts the laptop out
- scripts verified by Windows' own PowerShell parser on the NA Lighting PC

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_schema.py

@@ -177,7 +177,7 @@ class TestSchemaMatchesCode(unittest.TestCase):
 
     def test_every_declared_key_is_read_somewhere(self):
         """Dead settings are caught; keys only the settings page uses are listed here."""
-        ui_only = {"site.id", "site.name", "site.ingest_hostname", "site.ingest_ips", "site.contacts", "site.editing_code",
+        ui_only = {"site.id", "site.name", "site.ingest_hostname", "site.ingest_ips", "site.admin_ips", "site.admin_keys", "site.contacts", "site.editing_code",
                    "site.settings_port", "site.dvs_helper", "site.solo_dir", "hosts.*.name", "hosts.*.role",
                    "hosts.*.notes", "hosts.*.pingable", "hosts.*.runs", "hosts.*.networks", "hosts.*.manual_done",
                    "gear", "gear.*.location", "gear.*.notes", "gear.*.kind", "gear.*.address", "ready.ltc_campuses[].name", "ready.ltc_campuses[].short", "ready.ltc_campuses[].service_type", "atem.source_folder", "fixes.*.template", "fixes.*.params",