feat(cli): Add minimal CLI for memori - init, --version, and health commands (#132)

[ritoban23]

Overview

Implements issue #132 by adding a minimal CLI with three essential commands.

Changes

• memori --version: Display package version
• memori init [--force]: Create starter memori.json config
• memori health [--config <path>] [--check-db]: Validate environment and configuration
• Console script automatically available after pip install memorisdk
• 26 comprehensive unit tests (all passing)
• Complete CLI documentation and troubleshooting guide

Testing

• All 26 tests pass ✅
• Manual testing verified all commands work correctly
• CI/CD ready with proper exit codes

Files Changed

• memori/cli.py (new) - Main CLI implementation
• tests/unit/test_cli.py (new) - Comprehensive tests
• docs/getting-started/cli-reference.md (new) - CLI documentation
• pyproject.toml (modified) - Console script registration
• CHANGELOG.md (modified) - Feature entry
• docs/getting-started/quick-start.md (modified) - CLI mention
• mkdocs.yml (modified) - Navigation update

Closes #132