Clarify custom roles additive permission model

[mintlify]

Summary

• Expanded the additive permissions note into a full section explaining how custom roles interact with org-level permissions
• Added a practical example (Google Sheets export) showing why toggling off a scope in a custom role may have no effect
• Added step-by-step guidance for restricting permissions: downgrade org role to Viewer/Member, then use custom project roles to grant specific access
• Added a new troubleshooting entry for when custom roles don't restrict permissions as expected

[github-actions]

🤖 Documentation Bot

✅ All checks passed! No issues found.

[mintlify]

Preview deployment for your docs. Learn more about Mintlify Previews.

Project	Status	Preview	Updated (UTC)
lightdash	🟢 Ready	View Preview	Mar 27, 2026, 5:03 PM