[BUG] Long silent stretches during large tasks; harness repeatedly prompts for status

Re-filing #97131, closed as needing more information.

Environment

• Claude Code: 2.1.280
• Model: claude-opus-5-5[1m]
• OS: macOS 26.6.2
• Instructions loaded: project CLAUDE.md plus auto-memory MEMORY.md (both present in context at session start)

Steps to reproduce

1. Give the model a multi-step task that needs many tool calls (e.g. review three stacked pull requests: fetch, read diffs, fetch docs, run test suites).
2. Do not interrupt.

Actual

The model runs 10+ tool calls with no user-visible text. The harness injects "The user hasn't heard from you in a while" reminders several times in one turn (observed 6+ times in a single session today).

Expected

Short progress notes at a reasonable cadence without harness nudges.

Raised with Claude Code