feat(memory): add memory extension with core functionality and tests

- Implemented MemoryStore class for managing concepts with YAML frontmatter.
- Added methods for creating, reading, updating, and deleting concepts.
- Introduced locking mechanism for concurrent access.
- Developed search and hinting capabilities for concept retrieval.
- Created tests for access control and store functionality.
- Added long-term memory skill documentation and operational guidelines.
- Included package.json and package-lock.json for dependency management.

.gitignore

@@ -10,7 +10,9 @@ models-store.json
 npm/
 git/
 
-# Runtime files
+# Runtime files and local personal memory
+node_modules/
+/memory/
 pi-debug.log
 *.log
 .DS_Store