- Restrict --keyid flag to PGP unlocker type only
- Add validation to prevent --keyid usage with non-PGP unlockers
- Implement 'secret move' command with 'mv' and 'rename' aliases
- Add comprehensive tests for move functionality
- Update documentation to reflect optional nature of --keyid for PGP
The move command allows renaming or moving secrets within a vault while
preserving all versions and metadata. It fails if the destination already
exists to prevent accidental overwrites.