- replace watch_paths parameter with single watch_path string
- add FileGraph integration for tracking file relationships
- implement persistent graph storage in .reme directory
- add load/build graph functionality on start
- refactor file change handling with separate methods for add/modify/delete
- update scan_existing_files to work with single path
- add file filter to exclude meta directory from watching
- remove abstract method requirement and implement concrete change handlers
BREAKING CHANGE: watch_paths parameter changed to watch_path (single path)