Multi-user mode: v7 has no controls to share boards or workflows #9673

Summary

In multi-user mode, v7 has no controls for sharing boards or workflows. v6 had both:

• Boards: right-clicking a board let its owner set visibility to Private, Shared (others can view), or Public (others can view; the owner keeps control of rename/archive/delete).
• Workflows: a workflow's owner could mark it as shared (public), so it showed up in every user's workflow library as read-only.

In v7 the board context menu has no visibility options, and the workflow library has no sharing toggle. Boards and workflows a user creates in v7 stay private: only the owner and administrators can see them.

The backend still supports both. PATCH /boards/{id} accepts board_visibility, and workflow records carry is_public, which invokeai/app/api/routers/workflows.py checks for access. The gap is only in the webv2 UI.

Reproduction

1. Start InvokeAI with multiuser: true and log in as a regular user.
2. Right-click a board in the gallery. There is no visibility option.
3. Open the workflow library or a saved workflow. There is no share/public toggle.
4. Log in as a second regular user. None of the first user's boards or workflows appear.

Expected (v6 behaviour)

Owners can set board visibility and share workflows, as described in the multi-user user guide (Configuration → Multi-User Mode → User Guide, "Working with Your Content in Multi-User Mode").

Until this is fixed, the gap is listed on Troubleshooting → Known Bugs.