Improve user visibility and email privacy with group-based filtering

[romainsady]

What type of request is this?

New feature idea

Clear and concise description of the feature you are proposing

Currently, all connected users and their email addresses may be visible globally, including to guest users. This can raise privacy concerns and limit the use of the platform in collaborative contexts involving external participants.

Problems

• Email addresses are sensitive data and should not be exposed by default
• Guest users may see internal users they should not be aware of
• No control over visibility scope (global vs group-based)

Proposed solution

Introduce configurable visibility rules:

1. Email visibility control
   - public / authenticated / group_only / private
2. User listing scope
   - global (current behavior)
   - group_only (only users sharing at least one group)
   - restricted (future extension)
3. Guest restrictions
   - self_only visibility by default
   - no email access

Benefits

• Improved privacy and security
• Better support for external collaboration
• Flexible configuration without breaking existing behavior

Validations

• Check the feature is not already implemented in the project.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.
• Check that the feature is technically feasible and aligns with the project's goals.