diff --git a/app/Models/Concerns/HasUniqueSlug.php b/app/Models/Concerns/HasUniqueSlug.php
index c813021c..066d7462 100644
--- a/app/Models/Concerns/HasUniqueSlug.php
+++ b/app/Models/Concerns/HasUniqueSlug.php
@@ -86,10 +86,9 @@ trait HasUniqueSlug
      */
     protected function slugExists(string $slug, array $scope): bool
     {
-        /** @var Model $self */
         $self = $this;
 
-        $query = $self::query()
+        $query = static::query()
             ->withoutGlobalScopes()
             ->where($this->slugColumn(), $slug);
 
diff --git a/phpunit.xml b/phpunit.xml
index 648c4405..1ca5f122 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -31,6 +31,9 @@
         <env name="DB_DATABASE" value=":memory:" force="true"/>
         <server name="DB_CONNECTION" value="sqlite" force="true"/>
         <server name="DB_DATABASE" value=":memory:" force="true"/>
+        <!-- DB_URL würde Treiber und Datenbank beim Verbindungsaufbau überschreiben (Audit 02.10.2026, O02). -->
+        <env name="DB_URL" value="" force="true"/>
+        <server name="DB_URL" value="" force="true"/>
         <env name="MAIL_MAILER" value="array"/>
         <env name="PULSE_ENABLED" value="false"/>
         <env name="QUEUE_CONNECTION" value="sync"/>
diff --git a/tests/Feature/PressReleaseShowPhase8aTest.php b/tests/Feature/PressReleaseShowPhase8aTest.php
index f602dfb3..07c610fd 100644
--- a/tests/Feature/PressReleaseShowPhase8aTest.php
+++ b/tests/Feature/PressReleaseShowPhase8aTest.php
@@ -4,9 +4,6 @@ use App\Enums\Portal;
 use App\Enums\PressReleaseClassification;
 use App\Enums\PressReleaseContentTier;
 use App\Enums\PressReleaseStatus;
-use App\Models\Category;
-use App\Models\Company;
-use App\Models\Contact;
 use App\Models\PressRelease;
 use App\Models\User;
 use Database\Seeders\RolesAndPermissionsSeeder;
@@ -18,35 +15,6 @@ beforeEach(function (): void {
     $this->seed(RolesAndPermissionsSeeder::class);
 });
 
-/**
- * @return array{customer: User, company: Company, contact: Contact, category: Category, pr: PressRelease}
- */
-function makeCustomerForShowPhase8a(array $prAttributes = []): array
-{
-    $customer = User::factory()->create(['is_active' => true]);
-    $customer->assignRole('customer');
-
-    $company = Company::factory()->presseecho()->create();
-    $customer->companies()->attach($company->id, ['role' => 'owner']);
-
-    $contact = Contact::factory()->for($company)->create([
-        'portal' => $company->portal->value,
-    ]);
-    $category = Category::factory()->create();
-
-    $pr = PressRelease::factory()->create(array_merge([
-        'user_id' => $customer->id,
-        'company_id' => $company->id,
-        'category_id' => $category->id,
-        'portal' => $company->portal->value,
-        'status' => 'draft',
-    ], $prAttributes));
-
-    $pr->contacts()->sync([$contact->id]);
-
-    return compact('customer', 'company', 'contact', 'category', 'pr');
-}
-
 function makeAdminForShowPhase8a(): User
 {
     $admin = User::factory()->create(['is_active' => true]);
diff --git a/tests/Feature/TestDatabaseGuardTest.php b/tests/Feature/TestDatabaseGuardTest.php
index e2403171..c4d0a1d9 100644
--- a/tests/Feature/TestDatabaseGuardTest.php
+++ b/tests/Feature/TestDatabaseGuardTest.php
@@ -33,3 +33,24 @@ test('the database guard rejects anything but sqlite in memory', function () {
         config()->set('database.default', 'sqlite');
     }
 });
+
+test('the database guard rejects a url override on the sqlite connection', function () {
+    /** @var TestCase $this */
+    $guard = fn () => $this->assertTestDatabaseIsInMemorySqlite();
+
+    // Laravel löst `url` erst beim Verbindungsaufbau auf und überschreibt
+    // damit Treiber und Datenbank — die rohen sqlite/:memory:-Werte allein
+    // beweisen nichts (Umsetzungsaudit 02.10.2026, O02). Nur Config, keine
+    // Verbindung: der Guard muss vorher abbrechen.
+    try {
+        config()->set('database.connections.sqlite.url', 'mysql://root:secret@127.0.0.1:3306/pressekonto');
+
+        expect($guard)->toThrow(RuntimeException::class, 'DB_URL');
+    } finally {
+        config()->set('database.connections.sqlite.url', null);
+    }
+});
+
+test('phpunit neutralises DB_URL for the whole run', function () {
+    expect(config('database.connections.sqlite.url'))->toBeEmpty();
+});
diff --git a/tests/Pest.php b/tests/Pest.php
index 14ffefae..e0a4569a 100644
--- a/tests/Pest.php
+++ b/tests/Pest.php
@@ -1,6 +1,10 @@
 <?php
 
+use App\Models\Category;
+use App\Models\Company;
+use App\Models\Contact;
 use App\Models\Plan;
+use App\Models\PressRelease;
 use App\Models\User;
 use App\Services\CurrentPortalContext;
 use App\Support\WebPageCache;
@@ -86,3 +90,38 @@ function webPageCacheKey(string $key): string
 {
     return 'web.g'.WebPageCache::generation().'.'.substr($key, strlen('web.'));
 }
+
+/**
+ * Kunde (Rolle customer, Owner einer Presseecho-Firma) mit Kontakt, Kategorie
+ * und einer Entwurfs-PM. Gemeinsam genutzt von den Phase-8a-/8i-Tests und dem
+ * Widerrufsverzicht-Test — deshalb hier und nicht in einer einzelnen Testdatei,
+ * sonst scheitern die Nutzer im Einzel- oder Parallellauf.
+ *
+ * @param  array<string, mixed>  $prAttributes
+ * @return array{customer: User, company: Company, contact: Contact, category: Category, pr: PressRelease}
+ */
+function makeCustomerForShowPhase8a(array $prAttributes = []): array
+{
+    $customer = User::factory()->create(['is_active' => true]);
+    $customer->assignRole('customer');
+
+    $company = Company::factory()->presseecho()->create();
+    $customer->companies()->attach($company->id, ['role' => 'owner']);
+
+    $contact = Contact::factory()->for($company)->create([
+        'portal' => $company->portal->value,
+    ]);
+    $category = Category::factory()->create();
+
+    $pr = PressRelease::factory()->create(array_merge([
+        'user_id' => $customer->id,
+        'company_id' => $company->id,
+        'category_id' => $category->id,
+        'portal' => $company->portal->value,
+        'status' => 'draft',
+    ], $prAttributes));
+
+    $pr->contacts()->sync([$contact->id]);
+
+    return compact('customer', 'company', 'contact', 'category', 'pr');
+}
diff --git a/tests/TestCase.php b/tests/TestCase.php
index dca76039..42bd3dd0 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -44,6 +44,16 @@ abstract class TestCase extends BaseTestCase
         $default = (string) DB::getDefaultConnection();
         $connection = (array) config('database.connections.'.$default, []);
 
+        // Eine gesetzte `url` überschreibt Treiber und Datenbank erst beim
+        // Verbindungsaufbau — dann wären die geprüften Rohwerte wertlos
+        // (Umsetzungsaudit 02.10.2026, O02).
+        if (! empty($connection['url'])) {
+            throw new RuntimeException(sprintf(
+                'Tests laufen mit DB_URL-Override auf „%s“ — die Verbindung würde nicht SQLite :memory: sein. DB_URL für Tests leeren.',
+                $default,
+            ));
+        }
+
         if ($default !== 'sqlite' || ($connection['driver'] ?? null) !== 'sqlite' || ($connection['database'] ?? null) !== ':memory:') {
             throw new RuntimeException(sprintf(
                 'Tests laufen gegen „%s“ (%s) statt SQLite :memory: — vermutlich liegt ein Config-Cache. `php artisan config:clear` und erneut starten.',