feat: Add Ollama integration and improve CLI usability and documentation

- Added full support for Ollama via official Python client (`ollama>=0.4.8`)
- New agent class `OllamaAgent` for local LLMs like LLaMA3 via Ollama
- Refactored `AgentBuilder` to support multiple backends (phi, ollama)
- Improved CLI with:
  - `--ollama` and `--model` flags
  - Host configuration via `--ollama-host`
  - Structured prompt help and error handling
- Updated README with new usage examples, clearer feature list, and Ollama setup instructions
- Renamed `phi_4_mini.py` → `phi_4_mini_agent.py` for consistency
- Enhanced logging and feedback for model loading and errors
- Improved UX: response formatting, keypress actions (copy/execute/abort) with better feedback

Update README.md

fix: add freeze_support to handle multiprocessing in PyInstaller builds

Ensure that helper processes spawned by multiprocessing (e.g., for HuggingFace downloads)
do not accidentally re-execute the main CLI logic when running the frozen binary.

token added

token added

token added