Fix tenant event form package selector so it no longer renders empty-value options, handles loading/empty

states, and pulls data from the authenticated /api/v1/tenant/packages endpoint.
    (resources/js/admin/pages/EventFormPage.tsx, resources/js/admin/api.ts)
  - Harden tenant-admin auth flow: prevent PKCE state loss, scope out StrictMode double-processing, add SPA
    routes for /event-admin/login and /event-admin/logout, and tighten token/session clearing semantics (resources/js/admin/auth/{context,tokens}.tsx, resources/js/admin/pages/{AuthCallbackPage,LogoutPage}.tsx,
    resources/js/admin/router.tsx, routes/web.php)

public/lang/de/auth.json

@@ -6,7 +6,8 @@
     "occasions": {
       "wedding": "Hochzeit",
       "birthday": "Geburtstag",
-      "corporate": "Firmenevent"
+      "corporate": "Firmenevent",
+      "label": "Anlässe"
     },
     "contact": "Kontakt",
     "login": "Anmelden",
@@ -134,4 +135,4 @@
     "notice": "Bitte bestätigen Sie Ihre E-Mail-Adresse.",
     "resend": "E-Mail erneut senden"
   }
-}
+}