Auto-compact triggers mid-task causing context loss and hallucinations

Problem

Auto-compact (automatic conversation summarization) triggers in the middle of active tasks, causing severe context loss that leads to:

1. Hallucinations - Claude loses track of what was actually done vs what needs to be done
2. Task derailment - Work goes "to la la land" because critical context is lost in the summary
3. Workflow disruption - Defeats purpose of checkpoint/handover workflows designed to preserve context

Current Behavior

• Auto-compact triggers automatically based on token limits (no user control)
• No warning before compaction happens
• No way to disable or configure when it triggers
• Summarization loses critical details that break task continuity
• Not documented in public docs or exposed in settings

Impact

Severe UX problem for complex multi-stage workflows:

User: "Continue from where we left off"
Claude: [Reads auto-generated summary]
Claude: [Proceeds based on incomplete/incorrect context]
User: "Wait, that's wrong - you're hallucinating"

The summary mechanism appears to:

• Lose track of file modifications
• Lose intermediate decisions and rationale
• Lose specific technical details
• Conflate what was planned vs what was actually implemented

Expected Behavior

Option 1: User control (preferred)

• Add autoCompact setting to ~/.claude/settings.json:

``json
{
"autoCompact": {
"enabled": false,
"threshold": 150000 // token count
}
}
``

Option 2: Better summarization

• Preserve critical state information
• Include file modification history
• Maintain task progress tracking
• Keep technical implementation details

Option 3: User prompting

• Warn before auto-compact triggers
• Ask user if they want to compact now or start new session
• Give option to save checkpoint first

Workarounds

Users currently must:

1. Use /rewind to go back before compaction (loses all subsequent work)
2. Start fresh chat with manual context (time-consuming, error-prone)
3. Build elaborate checkpoint/handover workflows (shouldn't be necessary)

Environment

• Claude Code CLI
• Multi-hour development sessions with complex state
• Project with mandatory 5-stage development workflow
• Multiple repositories with cross-references

Feature Request

Please either:

1. Add settings to disable auto-compact
2. Add settings to configure compaction threshold
3. Improve summarization to preserve critical context
4. Add user prompting before auto-compact triggers

The current behavior breaks complex development workflows where context preservation is critical.