feat: register CalendarToken and OIDCOfflineToken in admin

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: schliz

src/shiftings/accounts/admin.py

@@ -1,5 +1,19 @@
 from django.contrib import admin
 
-from shiftings.accounts.models import User
+from shiftings.accounts.models import CalendarToken, OIDCOfflineToken, User
 
 admin.site.register(User)
+
+
+@admin.register(CalendarToken)
+class CalendarTokenAdmin(admin.ModelAdmin):
+    list_display = ('user', 'token', 'created')
+    search_fields = ('user__username',)
+    readonly_fields = ('created',)
+
+
+@admin.register(OIDCOfflineToken)
+class OIDCOfflineTokenAdmin(admin.ModelAdmin):
+    list_display = ('user', 'updated')
+    search_fields = ('user__username',)
+    readonly_fields = ('updated',)