Streamlit UI Interface and Other Small Changes

[nik1t7n]

feat: Add Streamlit web interface with advanced features

• Add modern web-based UI using Streamlit with dark theme support
• Implement live streaming of reasoning and response generation
• Add top (default: 20) weekly models fetching from OpenRouter with caching
• Create model name recognition with provider prefix detection
• Integrate token usage tracking for each interaction (input, reasoning, output)
• Add metadata display for each response (model used, tokens consumed)
• Implement toggle for reasoning visibility
• Add expandable sidebar with model and interface settings
• Create convenient model selection via dropdown or manual input
• Add .env.example file for easier configuration
• Improve code organization with proper docstrings
• Update README.md with Streamlit interface documentation

The web interface provides a more user-friendly way to interact with RAT while maintaining all the power of the original CLI version.