handle version in cli

CHANGELOG.md

@@ -7,6 +7,30 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- **New CLI Command**: `deltaglider migrate` for S3-to-S3 bucket migration with compression
+  - Supports resume capability (skips already migrated files)
+  - Real-time progress tracking with file count and statistics
+  - Interactive confirmation prompt (use `--yes` to skip)
+  - Prefix preservation by default (use `--no-preserve-prefix` to disable)
+  - Dry run mode with `--dry-run` flag
+  - Include/exclude pattern filtering
+  - Shows compression statistics after migration
+- **S3-to-S3 Recursive Copy**: `deltaglider cp -r s3://source/ s3://dest/` now supported
+  - Automatically uses migration functionality with prefix preservation
+  - Applies delta compression during transfer
+- **Version Command**: Added `--version` flag to show deltaglider version
+  - Usage: `deltaglider --version`
+
+### Changed
+- Recursive S3-to-S3 copy operations now preserve source prefix structure by default
+- Migration operations show formatted output with source and destination paths
+
+### Documentation
+- Added comprehensive migration guide in README.md
+- Updated CLI reference with migrate command examples
+- Added prefix preservation behavior documentation
+
 ## [5.1.1] - 2025-01-10
 
 ### Fixed