feat: implement selective memory management hooks/commands (pop/forget memory)

[lroolle]

Description

Add hooks and custom commands to enable selective memory management as an alternative to full conversation compacting.

Type

• Bug fix
• New feature
• Enhancement
• Documentation

Details

Currently Claude Code only supports full conversation compacting via /compact command. The main issue is that auto-compacting heavily impacts current working state - losing critical context about ongoing implementation, debugging sessions, and project decisions that are essential for the current task.

Current State:

• /compact performs full conversation summarization, disrupting active work
• /clear resets entire conversation
• Auto-compact triggers interrupt current workflows and lose working context
• PreCompact hook exists but limited to modifying full compaction

Community Evidence:
The community has built extensive workarounds due to this limitation:

• mcp-memory-keeper - SQLite-based persistent context (most popular)
• claude-memory-mcp - Advanced tiered memory architecture
• memory-bank-mcp - Remote memory management
• zen-mcp-server - Multi-model collaboration with persistence
• Users report "62-agent systems" built to compensate for context loss
• Multiple GitHub issues: #1345 (context management bugs), #1534 (memory loss after auto-compact)
• Community describes current system as "nearly unusable for complex tasks"

Root Problem:
Auto-compacting destroys working state context that's critical for ongoing tasks. Users need granular control to preserve current work while removing irrelevant history.

Proposed Solution:
Implement selective memory management through:

1. Selective Removal Commands:

   /forget          # Remove last interaction
   /forget 3        # Remove last 3 interactions  
   /forget <tag>    # Remove tagged conversation segment
   /checkpoint      # Create named restoration point
   /restore <name>  # Restore to checkpoint

2. Context Tagging System:

   /tag start debugging-session
   # ... debugging conversation ...
   /tag end debugging-session
   /forget debugging-session  # Remove entire tagged section

3. Working State Preservation:

   /scope working   # Mark current context as critical working state
   /scope temp      # Mark interactions as removable
   /cleanup temp    # Remove temporary while preserving working state

Technical Implementation:

• Extend PreCompact hook for selective manipulation
• Add transcript parsing for targeted removal
• Implement conversation metadata tracking
• Use existing CLAUDE.md system for persistent context
• Leverage MCP servers for external memory management

Benefits:

• Preserve working state during memory management
• Maintain project context while removing clutter
• User control over what stays vs what gets removed
• Reduce need for complex external memory systems
• Keep critical debugging/implementation context intact

Related Files

• Hook system and PreCompact implementation
• Custom command handlers (.claude/commands/)
• Memory management utilities
• Transcript manipulation functions

Test Plan

• Test /forget commands preserve current working context
• Verify tagging system protects critical conversation segments
• Test checkpoint/restore maintains working state
• Ensure persistent memory (CLAUDE.md) is preserved
• Test working state preservation during selective removal
• Validate conversation coherence after targeted forgetting
• Test integration with existing hooks and MCP servers
• Document command syntax and working state protection patterns

Main Goal: Enable users to manage conversation memory without losing critical working state that's essential for current tasks.

References: Community solutions (mcp-memory-keeper, claude-memory-mcp), GitHub issues #1345/#1534, PreCompact hook (v1.0.48)