Feature Request: Make terminal scrollback clearing on compaction configurable

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 Claude Code compacts a session (manually via /compact or automatically), it clears not just the visible terminal screen but also the scrollback buffer. This means I lose access to:

• What I started working on at the beginning of the session
• Previous commands and their outputs
• Context about when/why compaction happened
• The full audit trail of the session

The terminal is a shared workspace — it belongs to the human, not just Claude. I need to scroll back to reference earlier context, especially after long sessions where compaction happens automatically.

Proposed Solution

A configuration option to control terminal clearing behavior during compaction:

// settings.json
{
  "compaction": {
    "clearScrollback": false  // default: true (current behavior)
  }
}

Or via CLI flag:

claude --no-clear-scrollback

The interface should preserve terminal scrollback history while still performing the context compaction internally.

Alternative Solutions

• iTerm2 automatic session logging — Captures to file, but clunky to reference compared to native scrollback
• iTerm2 Instant Replay — Only works if caught immediately after compaction
• PreCompact hook — Can timestamp when compaction happens, but can't prevent scrollback clearing

None of these preserve the natural terminal scrollback UX.

Priority

High — This affects every long session where compaction occurs, and the lost context is often critical for continuing work effectively.

Feature Category

Terminal / Display / UX

Use Case Example

Example scenario:

1. I start a Claude Code session to work on a complex refactoring task
2. I discuss the approach, run several commands, review outputs
3. After 30+ minutes, context fills up and auto-compaction triggers
4. I need to reference an earlier command output or remember what we initially planned
5. With this feature, I could scroll up in iTerm2 and see the full session history
6. This would save me time because I wouldn't need to re-ask questions or re-run commands

Additional Context

• Environment: macOS + iTerm2, Claude Code (latest)
• Technical detail: The scrollback clearing appears to use \033[3J escape sequence
• Similar behavior: Other CLI tools (vim, less, etc.) don't clear scrollback when exiting — they restore the previous terminal state