Bump version to 5.5.1

This patch release includes:
- Summary hook enhancements to capture last user message from transcripts
- Activity indicator improvements for better user feedback
- Worker service enhancements for queue depth tracking

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

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

plugin/.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "claude-mem",
-  "version": "5.5.0",
+  "version": "5.5.1",
   "description": "Persistent memory system for Claude Code - seamlessly preserve context across sessions",
   "author": {
     "name": "Alex Newman"