Grouped Agent Display

What: When multiple Task agents run simultaneously, the UI now shows a collapsed summary view that can be expanded with ctrl+o.

How it appears:

Running 3 agents… (ctrl+o to expand)
├─ investigator (Check auth flow) · 5 tool uses · 2.3k tokens
├─ investigator (Find routes) · 3 tool uses · 1.8k tokens
└─ investigator (Review tests) · 7 tool uses · 3.1k tokens

Details:

• Reduces visual clutter when multiple agents run in parallel
• Shows agent type, description, tool use count, and token usage
• Displays "X agents finished" when complete
• Same-type agents show grouped label (e.g., "Running 3 investigator agents…")
• Evidence: Main renderer i49() at line 469450, item renderer g49() at line 469102