Add comprehensive test coverage and update notes

tests/Feature/SettingControllerTest.php

@@ -87,3 +87,16 @@ it('bulk stores settings as admin', function (): void {
         'value' => 'Fast',
     ]);
 });
+
+it('bulk store forbids non-admin users', function (): void {
+    $user = User::factory()->create();
+    Sanctum::actingAs($user);
+
+    $response = $this->postJson('/api/settings/bulk', [
+        'settings' => [
+            ['key' => 'site.name', 'value' => 'SpeedBB'],
+        ],
+    ]);
+
+    $response->assertStatus(403);
+});