5.9 Notifications and user self-service

# 5.9 Notifications and user self-service

**Parent:** Story 5 (#7232)
**Tool file:** new `forge/ee/lib/mcp/tools/user.js`

## Summary

Self-service tools operating on the authenticated user's own account: profile, notifications, and pending team invitations. `list-teams` (`GET /user/teams`) already ships. Sibling write endpoints that share one concept (notification mark-read variants, accept/reject invitation) are consolidated into single action tools; deletes are grouped into a separate destructive tool.

Start with forge/ee/lib/mcp/tools/user.js and the existing list-teams tool for GET /user/teams. Trace the authenticated-user endpoints for profile, notifications, pending team invitations, sibling mark-read actions, invitation decisions, and grouped deletes. Done means the self-service tools and consolidated actions described in the issue are available in that file.

Written by the indexing model from the issue text.