Write PHPUnit tests for Glueful — distinguishing consumer-app tests (extend App\Tests\TestCase / Glueful\Testing\TestCase, boot the real app) from framework/extension library tests (extend PHPUnit\Framework\TestCase, lightweight SQLite Connection harness). Covers the PHPUnit config an app needs, booting/mocking, and the TDD loop. Use when adding or fixing tests in a Glueful app or package. Uses PHPUnit 10, not Laravel's TestCase/RefreshDatabase.
