improve OCO_AI_PROVIDER=ollama[/model name] (#327)

* 🐛 (config.ts, engine/ollama.ts, utils/engine.ts): improve Ollama AI configuration and usage
✨ (config.ts): add support for multiple Ollama models and allow users to specify the model in their config
✅ (engine/ollama.ts, utils/engine.ts): refactor code to use the specified Ollama model instead of hardcoding it

* add build results

Author: tumf