Describe your use case

Developers and system administrators need a convenient way to interact with PowerMem from the command line without writing Python scripts. This would enable:

• Quick memory operations during development and debugging
• Batch operations and automation scripts
• System administration tasks (backup, migration, cleanup)
• Integration with shell scripts and CI/CD pipelines
• Quick testing and validation of PowerMem configurations

Describe the solution you'd like

Create a CLI tool (powermem-cli or pmem) that provides commands for:

1. Memory operations: add, search, update, delete
2. Configuration: config show, config validate, config test
3. Statistics: stats, stats user <user_id>, stats agent <agent_id>
4. Management: backup, restore, cleanup, migrate
5. Interactive mode: interactive or shell for REPL-like experience

Describe alternatives you've considered

Example usage:

powermem-cli add "User prefers dark mode" --user-id user123
powermem-cli search "user preferences" --user-id user123
powermem-cli stats --user-id user123

The CLI should:

• Use the same configuration system (.env file or environment variables)
• Support JSON output for scripting
• Provide helpful error messages and validation
• Include command completion (bash/zsh)
• Follow the existing PowerMem Python SDK patterns

Additional context

No response