When the Messenger shim is loaded with Turbo, the load event has already
fired, so adding an event listener for it won't have any effect. Instead
we can immediately add the script tag to the page.

Also stop calling Intercom('reattach_activator'), which is an obsolete
API that no longer does anything.

* Fix dev dependencies

* Support experimental JWT authentication for the messenger

* Remove user_id from regular user_data payload when using JWT

* Add some script tag helper specs too

* bump version

This reverts commit e73b28b.

This reverts commit d99af3b.

Co-authored-by: Damon Foster <DamonFstr@users.noreply.github.com>

Add comprehensive documentation for the JWT authentication feature that was previously implemented but undocumented. The new section covers:

- Basic JWT enablement configuration
- JWT expiry settings
- Signed user fields configuration for enhanced security
- Per-request JWT configuration options
- Important security notes and requirements

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Claude <noreply@anthropic.com>