scaffold laravel 12 backend

composer create-project laravel/laravel + artisan install:api.
sanctum removed (custom session-cookie auth per ai/backend-context).
personal_access_tokens migration + config/sanctum.php deleted.
default .gitignore excludes vendor/, .env, etc - composer install
recreates vendor at setup time.

backend/.gitignore

@@ -0,0 +1,24 @@
+*.log
+.DS_Store
+.env
+.env.backup
+.env.production
+.phpactor.json
+.phpunit.result.cache
+/.fleet
+/.idea
+/.nova
+/.phpunit.cache
+/.vscode
+/.zed
+/auth.json
+/node_modules
+/public/build
+/public/hot
+/public/storage
+/storage/*.key
+/storage/pail
+/vendor
+Homestead.json
+Homestead.yaml
+Thumbs.db