[FEATURE] Tree view for parallel agent monitoring

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

When running multiple agents in parallel, the current notification style
is hard to follow. Agent IDs are cryptic and updates scroll away.

Proposed Solution

A real-time tree view:

backend-developer (implementing ward CRUD API)
└── Writing: app/api/admin/wards/route.ts

admin-developer (building roster matrix view)
└── Editing: components/roster-matrix.tsx

Key improvements:

• Agent role labels instead of IDs
• Current action + file context
• In-place updates (not scrolling)

Alternative Solutions

_No response_

Priority

Low - Nice to have

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_