* Update email and text templates for Domain Claimed by Organization notification
- Changed the heading to "What this means for you" for clarity.
- Revised bullet points to better reflect user experience and responsibilities within the organization.
- Updated the phrasing of the help article reference for consistency.
* Fix HandlebarsMailService claimed domain email
feat(PM-21741): implement MJML welcome email templates with feature flag support
- Add MJML templates for individual, family, and organization welcome emails
- Track *.hbs artifacts from MJML build
- Implement feature flag for gradual rollout of new email templates
- Update RegisterUserCommand and HandlebarsMailService to support new templates
- Add text versions and sanitization for all welcome emails
- Fetch organization data from database for welcome emails
- Add comprehensive test coverage for registration flow
Co-authored-by: Rui Tomé <108268980+r-tome@users.noreply.github.com>
