feature/phpunit-tests
main
The custom autoloader used lowercase directory names which broke after renaming app/core/ → app/Core/ and app/controllers/ → app/Controllers/ for PSR-4 compliance.
- Add composer.json with PHPUnit 11 and PSR-4 autoloading - Add phpunit.xml configuration - Rename app/core/ → app/Core/ and app/controllers/ → app/Controllers/ (PSR-4) - Add 18 unit tests for App\Core\Router (31 assertions) - addRoute(): default action, custom action, overwrite - dispatch(): URL normalization, direct match, legacy redirects - dispatch(): 404 handling, controller/action not found exceptions - TestableRouter subclass to intercept side-effects - Update .gitignore (vendor/, .phpunit.cache/)