diff --git a/app/app/Console/Commands/CheckSupplierWebhookSecretCommand.php b/app/app/Console/Commands/CheckSupplierWebhookSecretCommand.php
new file mode 100644
index 00000000..6c671219
--- /dev/null
+++ b/app/app/Console/Commands/CheckSupplierWebhookSecretCommand.php
@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Console\Commands;
+
+use Illuminate\Console\Command;
+use Illuminate\Support\Facades\DB;
+
+/**
+ * Deploy-time validator для supplier_webhook_secret.
+ *
+ * Spec: docs/superpowers/specs/2026-05-10-supplier-integration-design.md §5.1.
+ * Plan 2.6 fix #i: closes CV.11 audit WARN #4 (placeholder seed на production
+ * → endpoint silent 404 на ВСЕ запросы из-за verifySecret в SupplierWebhookController).
+ *
+ * Использование в deploy-script: `php artisan supplier:check-webhook-secret`
+ *   exit code 0 = OK, exit code 1 = блокирующая ошибка (deploy не должен продолжаться).
+ *
+ * Проверки:
+ *   1. system_settings row существует с key='supplier_webhook_secret'.
+ *   2. value !== '__SET_ON_DEPLOY__' (placeholder из schema seed).
+ *   3. strlen(value) >= 32 chars (требование verifySecret в SupplierWebhookController).
+ */
+class CheckSupplierWebhookSecretCommand extends Command
+{
+    protected $signature = 'supplier:check-webhook-secret';
+
+    protected $description = 'Deploy-time validator: проверка supplier_webhook_secret seed (Plan 2.6 fix #i)';
+
+    public function handle(): int
+    {
+        $row = DB::table('system_settings')->where('key', 'supplier_webhook_secret')->first();
+
+        if ($row === null) {
+            $this->error('FAIL: system_settings row для key=supplier_webhook_secret не найдена. Schema seed повреждён или БД не мигрирована.');
+
+            return self::FAILURE;
+        }
+
+        $value = (string) $row->value;
+
+        if ($value === '__SET_ON_DEPLOY__') {
+            $this->error('FAIL: supplier_webhook_secret = "__SET_ON_DEPLOY__" (placeholder из schema seed). Override через UPDATE system_settings перед deploy.');
+
+            return self::FAILURE;
+        }
+
+        if (strlen($value) < 32) {
+            $this->error('FAIL: supplier_webhook_secret слишком короткий (length='.strlen($value).', нужно >=32 chars для совместимости с verifySecret в SupplierWebhookController).');
+
+            return self::FAILURE;
+        }
+
+        $this->info('OK: supplier_webhook_secret valid (length='.strlen($value).' chars, не placeholder).');
+
+        return self::SUCCESS;
+    }
+}
diff --git a/app/phpstan-baseline.neon b/app/phpstan-baseline.neon
index 20f7e7d1..86cae2ca 100644
--- a/app/phpstan-baseline.neon
+++ b/app/phpstan-baseline.neon
@@ -911,3 +911,9 @@ parameters:
 			identifier: method.notFound
 			count: 2
 			path: tests/Feature/Console/ResetDeliveredTodayCommandTest.php
+
+		-
+			message: '#^Call to an undefined method Pest\\PendingCalls\\TestCall\:\:artisan\(\)\.$#'
+			identifier: method.notFound
+			count: 4
+			path: tests/Feature/Console/CheckSupplierWebhookSecretCommandTest.php
diff --git a/app/tests/Feature/Console/CheckSupplierWebhookSecretCommandTest.php b/app/tests/Feature/Console/CheckSupplierWebhookSecretCommandTest.php
new file mode 100644
index 00000000..b12b0dd4
--- /dev/null
+++ b/app/tests/Feature/Console/CheckSupplierWebhookSecretCommandTest.php
@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+use Illuminate\Support\Facades\DB;
+
+uses(DatabaseTransactions::class);
+
+test('rejects placeholder seed __SET_ON_DEPLOY__', function () {
+    DB::table('system_settings')
+        ->updateOrInsert(
+            ['key' => 'supplier_webhook_secret'],
+            ['value' => '__SET_ON_DEPLOY__', 'type' => 'string', 'description' => 'test seed']
+        );
+
+    $this->artisan('supplier:check-webhook-secret')->assertExitCode(1);
+});
+
+test('rejects too-short secret (< 32 chars)', function () {
+    DB::table('system_settings')
+        ->updateOrInsert(
+            ['key' => 'supplier_webhook_secret'],
+            ['value' => 'short-secret-only-20-chars', 'type' => 'string', 'description' => 'test']
+        );
+
+    $this->artisan('supplier:check-webhook-secret')->assertExitCode(1);
+});
+
+test('rejects missing seed row', function () {
+    DB::table('system_settings')->where('key', 'supplier_webhook_secret')->delete();
+
+    $this->artisan('supplier:check-webhook-secret')->assertExitCode(1);
+});
+
+test('accepts valid secret (>=32 chars and not placeholder)', function () {
+    DB::table('system_settings')
+        ->updateOrInsert(
+            ['key' => 'supplier_webhook_secret'],
+            ['value' => str_repeat('a', 64), 'type' => 'string', 'description' => 'test seed']
+        );
+
+    $this->artisan('supplier:check-webhook-secret')->assertExitCode(0);
+});