Quickstart – Regex Command

Preview a capture-group rename before applying.
```
renamer regex '^(\d{4})-(\d{2})_(.*)$' 'Q@2-@1_@3' --dry-run
```
- Converts 2025-01_report.txt into Q01-2025_report.txt in preview mode.
- Skipped files remain untouched and are labeled in the preview table.
Limit scope with extension and directory flags.
```
renamer regex '^(build)_(\d+)_v(.*)$' 'release-@2-@1-v@3' --path ./artifacts --extensions .zip|.tar.gz --include-dirs --dry-run
```
- Applies only to archives under ./artifacts, including subdirectories when paired with -r.
- Hidden files remain excluded unless --hidden is added.
Apply changes non-interactively for automation.
```
renamer regex '^(feature)-(.*)$' '@2-@1' --yes --path ./staging
```
- --yes confirms using the preview plan and writes a ledger entry containing pattern and template metadata.
- Exit code 0 indicates success; non-zero signals validation or conflict issues.
Undo the last regex batch if results are unexpected.
```
renamer undo --path ./staging
```
- Restores original filenames using the .renamer ledger captured during apply.