Add new documentation sections covering security best practices and authentication system architecture. Update Sphinx configuration and dependencies to support documentation improvements.
Changes include:
- New security.rst with SSH key management, network security, secrets management
- New authentication.rst documenting pluggable auth system and provider setup
- Updated Sphinx config to use Alabaster theme and add sphinx-tabs extension
- Added docs extra dependencies in pyproject.toml for documentation builds
- Updated example configs to use Ed25519 instead of deprecated DSA keys
- Added .python-version file for consistent Python version management
- Added CLAUDE.md project instructions for AI-assisted development
- Minor Dockerfile cleanup removing commented pip install line
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
