Group invite notification remains unread after acceptance

[seifmaazouz]

Summary

Group invite notifications stay in the database with IsRead = false after the recipient accepts the invite.

Current behavior

• Accepting an invite only joins the group.
• Notification is neither marked read nor deleted.

Expected behavior

Choose one policy and implement it:

• Mark invite notification as read on accept (keep history), or
• Delete invite notification on accept, or
• Retain for a fixed period then purge.

Acceptance criteria

• On accept, the invite notification is updated according to the chosen policy.
• Pending invites list no longer shows the accepted invite.