fix: repair 4 pre-existing failing tests

- WorkOrderCalcTest: vehicle fixture used `brand` (column is `make`, NOT NULL)
  and WorkOrderPart used `price`/manual total (column is `sell_price`, total is
  auto-computed). Switched to correct columns + valid status.
- ExampleTest: stock test expected 200 on `/` but the central domain redirects
  to /admin. Replaced with a deterministic central-root → /admin redirect check.

Full suite now green: 99 passed, 0 failed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/Feature/ExampleTest.php

@@ -8,12 +8,12 @@ use Tests\TestCase;
 class ExampleTest extends TestCase
 {
     /**
-     * A basic test example.
+     * On the central domain, the root path redirects to the admin panel.
      */
-    public function test_the_application_returns_a_successful_response(): void
+    public function test_central_root_redirects_to_admin(): void
     {
-        $response = $this->get('/');
+        $response = $this->get('http://service.mir.md/');
 
-        $response->assertStatus(200);
+        $response->assertRedirect('/admin');
     }
 }