Release v6.4.0: Dual-tag system, search API improvements, and privacy features

This release introduces powerful new privacy controls and search improvements:

**New Features:**
- Dual-tag system for meta-observation control
  - <private> tags for user-level privacy control
  - <claude-mem-context> tags for system-level auto-injected observations
- Privacy tag documentation and inline help in context hook

**Improvements:**
- Simplified search API parameters to eliminate bracket encoding issues
- Improved user messaging for new privacy features

**Technical:**
- Tag stripping happens at hook layer (edge processing)
- Shared utilities in src/utils/tag-stripping.ts
- Database index optimization for user prompts lookup

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

CLAUDE.md

@@ -6,7 +6,7 @@
 
 Claude-mem is a Claude Code plugin providing persistent memory across sessions. It captures tool usage, compresses observations using the Claude Agent SDK, and injects relevant context into future sessions.
 
-**Current Version**: 6.3.7
+**Current Version**: 6.4.0
 
 ## Architecture