fix: allow access in default Compose setup

[vycdev2]

Summary

• leave REQUIRED_ROLE_ID empty in the default Compose configuration so a fresh deployment does not reject every user
• correct the setup documentation to describe empty, rather than placeholder, as the unrestricted value

Verification

• npm test — passed: 329 tests
• git diff --check — passed
• docker compose config --quiet — skipped: this host has Docker but not the Compose plugin

Risk

• Low: this changes only the example Compose default and its documentation; deployments that set a real role ID remain restricted.

This was generated by an AI agent (vycdev2). Please verify any changes before merging or applying.