[BUG] Multiple tool calls in single response shown as one collapsed summary line instead of individual steps

Description

When Claude executes multiple tool calls in a single response turn (file edits, git commands, bash, etc.), the terminal UI now shows them collapsed as a single one-line summary (e.g. _\"Edited 5 files +27 -23, committed bbbe19, pushed to feature/..., commented on PR #387, searched for 2 patterns, read 3 files, ran 12 bash commands\"_) rather than showing each tool call step-by-step as it runs.

Only the final text response is shown inline. All intermediate work is hidden behind the collapsed summary.

Steps to Reproduce

1. Start a Claude Code session
2. Ask Claude to perform a multi-step task (e.g. \"fix these issues and push\" — involves file edits, git add/commit/push, gh pr comment)
3. Observe the response: all tool calls are collapsed into a single summary line; only the closing prose is visible

Expected Behavior

Each tool call should be shown individually as Claude works through them, so the user can follow along in real-time (previous behavior). The summary line format previously only appeared for the _completed_ block in older/scrolled-out messages.

Actual Behavior

All tool calls in a multi-step response are immediately collapsed into one summary line. There is no way to watch individual steps execute live. The user only sees the final text paragraph.

Environment

• Claude Code version: latest (v2.1.x)
• OS: macOS (Darwin 25.3.0)
• Shell: zsh
• Model: claude-opus-4-6, claude-sonnet-4-6

Related Issues

• #41907 — aggressively hides previous output during session (similar theme, different symptom)
• #41814 — messages disappear from terminal after v2.1.89 (overlapping but different)

Notes

This makes it hard to verify what Claude did during a complex task without manually expanding the collapsed group (if an expand control is even available). The live step-by-step visibility was useful for catching mistakes mid-run.