[feature request] Configurable idle threshold for session recap auto-fire

Summary

The session recap (away summary) feature is very useful when returning to a session, but the auto-fire idle threshold appears to be fixed (a few minutes) and not user-configurable.

Feature request

Add a configurable threshold so users can tune when auto-recap fires. e.g.:

• awaySummaryIdleMinutes in settings.json (numeric, minutes)
• or a CLAUDE_CODE_AWAY_SUMMARY_IDLE_MINUTES environment variable

Use case

I find recap genuinely valuable for context restoration after pauses, but my workflow benefits from quicker firing during medium pauses (1-3 min), not only long idles. Currently I have to type /recap manually for short pauses, which works, but the auto-trigger is the right pattern; it just needs tuning.

Current behavior (verified)

• Toggle: /config -> Session recap, or awaySummaryEnabled: false in settings.json, or CLAUDE_CODE_ENABLE_AWAY_SUMMARY=0
• Manual: /recap
• Threshold: not exposed

Environment

• Claude Code 2.1.126
• macOS 25.4.0 (Apple Silicon)
• language: ja

Thanks for the feature — it is a great addition to long working sessions.