Add a minimal CLI: memori init, memori --version, and memori health

Summary

Propose adding a simple command-line interface for the memori package to improve onboarding, environment validation, and usability.

Motivation

• A CLI makes it easier for users to get started, check their setup, and validate their environment.
• The project already hints at CLI support in pyproject.toml.
• Common commands like init and health are standard in modern Python packages and help users quickly bootstrap and debug.

Proposed commands

• memori --version: Prints the package version.
• memori init: Creates a starter memori.json config in the current directory (does not overwrite unless --force is used).
• memori health: Checks config validity, module imports, and (optionally) database connectivity, printing a short report and returning a non-zero exit code on failure.

Implementation plan

• Add memori/cli.py using only the Python standard library (argparse, json, etc.).
• Register the CLI in pyproject.toml as a console script: memori = "memori.cli:main".
• Add basic tests for CLI commands.
• Update documentation with a short CLI usage section.
• CLI is available after install.
• Each command works as described and is covered by tests.
• Documentation includes CLI usage examples.

Please let me know if you support adding this CLI, or if you have suggestions for additional commands or changes.