feat(server): handle account deleting properly (#12399)

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

- **New Features**
  - Users are now prevented from deleting their account if they own one or more team workspaces. A clear error message instructs users to transfer ownership or delete those workspaces first.
  - Disabled (banned) users are explicitly prevented from signing in or re-registering.
  - Added new error messages and translations to improve clarity around account deletion restrictions.

- **Bug Fixes**
  - Disabled users are now explicitly handled to prevent sign-in attempts.

- **Tests**
  - Introduced comprehensive end-to-end tests covering account deletion, banning, and re-registration scenarios.

- **Chores**
  - Improved event handling for user deletion and subscription cancellation.
  - Updated localization resources with new error messages.
  - Renamed payment event handler class for clarity.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/i18n/src/i18n.gen.ts

@@ -8614,6 +8614,10 @@ export function useAFFiNEI18N(): {
       * `Cannot delete own account.`
       */
     ["error.CANNOT_DELETE_OWN_ACCOUNT"](): string;
+    /**
+      * `Cannot delete account. You are the owner of one or more team workspaces. Please transfer ownership or delete them first.`
+      */
+    ["error.CANNOT_DELETE_ACCOUNT_WITH_OWNED_TEAM_WORKSPACE"](): string;
     /**
       * `Captcha verification failed.`
       */

packages/frontend/i18n/src/resources/en.json

@@ -2128,6 +2128,7 @@
   "error.MAILER_SERVICE_IS_NOT_CONFIGURED": "Mailer service is not configured.",
   "error.CANNOT_DELETE_ALL_ADMIN_ACCOUNT": "Cannot delete all admin accounts.",
   "error.CANNOT_DELETE_OWN_ACCOUNT": "Cannot delete own account.",
+  "error.CANNOT_DELETE_ACCOUNT_WITH_OWNED_TEAM_WORKSPACE": "Cannot delete account. You are the owner of one or more team workspaces. Please transfer ownership or delete them first.",
   "error.CAPTCHA_VERIFICATION_FAILED": "Captcha verification failed.",
   "error.INVALID_LICENSE_SESSION_ID": "Invalid session id to generate license key.",
   "error.LICENSE_REVEALED": "License key has been revealed. Please check your mail box of the one provided during checkout.",