* Update launch.example.json with simplified environment variables
* Create localdev.md with step-by-step setup instructions for running it with a network-local environment
* Create release.md with release procedure documentation

* Add @ symbol to organizer display names
* Fix tab selector for 'notgoing' tab (was 'not_going')
* Make handle names clickable in RSVP list
* Improve HTML indentation consistency

- Add VS Code launch configuration example and settings
- Create detailed BUILD.md with setup instructions
- Add keys.example.json for configuration reference
- Update .gitignore to exclude development files
- Remove unused InvitationActiveKeys functionality from config