- Add Laravel\Cashier\Billable trait to Workspace model
- Register Workspace as Cashier customer model in AppServiceProvider
- Publish cashier config with EUR currency and de_DE locale defaults
- Add CSRF exclusion for stripe/* in bootstrap/app.php
- Add StripeWebhookTest verifying endpoint exists and rejects bad signatures
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>