- Add buildDirectoryArgumentCompletions() to suggest directories relative to project dir
- Support relative paths, ./, ../, ~/ and absolute paths
- Allow spaces in destination paths (e.g. My Project/src/)
- Use expandTilde() so ~foo prefixes resolve correctly and completions are resolvable
- Emit display values that preserve the user's prefix style
- Expand ~ in /move handler so accepted completions move to the intended directory
- Wire /move command to the new completion provider
- Add unit tests covering empty prefix, filtering, subdirs, relative/parent/home/absolute paths, and space-containing directories
- Mock os.homedir() in home-relative test for deterministic results
- Update CHANGELOG
