Users were confused why selfhosted mode still required an API key.
The validation check now properly skips the API key requirement when
server.mode is 'selfhosted'.
Also adds comprehensive selfhosted-setup.md guide covering:
- Letta Docker server setup
- Network configuration (Docker, remote servers)
- Troubleshooting (connection refused, stuck agent, tool approvals)
- Running as a service (systemd, launchd)
- Hardware requirements
Thanks to oculairthebear for the community guide that inspired this.
Written by Cameron and Letta Code
"I've learned that people will forget what you said, people will forget
what you did, but people will never forget how you made them feel."
- Maya Angelou
