feat: Phase 4 - CI/CD, Static Analysis, Browser Tests

- Add GitHub Actions CI workflow (.github/workflows/ci.yml)
  - Laravel Pint code style check
  - PHPStan static analysis (level 5)
  - Test suite with parallel execution
  - Dusk browser tests (disabled by default)
- Add phpstan.neon config (level 5, ignores User notifications methods)
- Add Dusk browser tests (ProjectWorkflowTest)
- Install laravel/dusk + chromedriver

Tests: 101 passing (319 assertions)

composer.json

@@ -26,11 +26,13 @@
     "require-dev": {
         "fakerphp/faker": "^1.23",
         "laravel/breeze": "^2.4",
+        "laravel/dusk": "^8.6",
         "laravel/pail": "^1.2.2",
         "laravel/pint": "^1.24",
         "laravel/sail": "^1.41",
         "mockery/mockery": "^1.6",
         "nunomaduro/collision": "^8.6",
+        "phpstan/phpstan": "^2.2",
         "phpunit/phpunit": "^11.5.50"
     },
     "autoload": {