feat: hide legacy licensing admin models

apps/licensing/admin.py

@@ -334,8 +334,15 @@ class ReadOnlyLicenseAdmin(admin.ModelAdmin):
         return False
 
 
+class HiddenLegacyLicenseAdmin(ReadOnlyLicenseAdmin):
+    """Keep legacy records addressable without advertising them in admin."""
+
+    def get_model_perms(self, request):
+        return {}
+
+
 @admin.register(LicenseSeat)
-class LicenseSeatAdmin(ReadOnlyLicenseAdmin):
+class LicenseSeatAdmin(HiddenLegacyLicenseAdmin):
     list_display = ("entitlement", "seat_number", "device", "bound_at", "released_at")
     list_filter = ("entitlement__product_code", "bound_at", "released_at")
     search_fields = (
@@ -363,7 +370,7 @@ class LegacyMigrationGrantForm(EntitlementGrantForm):
 
 
 @admin.register(LegacyMigrationGrant)
-class LegacyMigrationGrantAdmin(ReadOnlyLicenseAdmin):
+class LegacyMigrationGrantAdmin(HiddenLegacyLicenseAdmin):
     list_display = ("user", "product_code", "entitlement", "status", "actor", "created_at")
     list_filter = ("product_code", "status", "created_at")
     search_fields = ("user__username", "user__email", "reason")
@@ -410,7 +417,7 @@ class LegacyMigrationGrantAdmin(ReadOnlyLicenseAdmin):
 
 
 @admin.register(MigrationRequest)
-class MigrationRequestAdmin(ReadOnlyLicenseAdmin):
+class MigrationRequestAdmin(HiddenLegacyLicenseAdmin):
     list_display = ("request_id", "user", "device", "migration_grant", "status", "expires_at", "confirmed_at")
     list_filter = ("status", "device__product_code", "expires_at")
     search_fields = ("=request_id", "user__username", "user__email")
@@ -418,7 +425,7 @@ class MigrationRequestAdmin(ReadOnlyLicenseAdmin):
 
 
 @admin.register(DeviceCredential)
-class DeviceCredentialAdmin(ReadOnlyLicenseAdmin):
+class DeviceCredentialAdmin(HiddenLegacyLicenseAdmin):
     list_display = ("token_prefix", "user", "product_code", "device", "entitlement", "expires_at", "revoked_at")
     list_filter = ("product_code", "revoked_at", "expires_at")
     search_fields = ("token_prefix", "user__username", "user__email")