Project invitation endpoint crashes with SoftDeletionQuerySet.role on v1.3.1

Summary

In Plane Community v1.3.1, creating a project invitation through the application endpoint fails with HTTP 500.

Affected route

POST /api/workspaces/{workspace_slug}/projects/{project_id}/invitations/

Observed behavior

The request fails before persisting an invitation with:

AttributeError: 'SoftDeletionQuerySet' object has no attribute 'role'

The failure is in plane/app/views/project/invite.py:60-64, where the code accesses .role on the WorkspaceMember.objects.filter(...) queryset.

Expected behavior

A workspace/project admin should be able to create a project invitation for a valid email and permitted role, returning a successful invitation response.

Reproduction

1. Run Plane Community v1.3.1.
2. Sign in as a workspace and project admin.
3. POST a valid emails payload to the route above.
4. Observe HTTP 500 and no persisted invitation.

Safe workaround

Create a workspace invitation first, complete the invite-gated signup and workspace join, then add the existing workspace member to the project through the session-authenticated project-members endpoint with the same allowed role.

No credentials, internal addresses, or deployment-specific identifiers are included.

Read plane/app/views/project/invite.py:60-64 and reproduce the POST request against the listed invitations route. Inspect the WorkspaceMember.objects.filter(...) usage and its role access, then verify the endpoint returns a successful invitation response and persists the invitation for a permitted role without the AttributeError.