Optimize model loading and error handling in PoetryGenerationService; implement async poem generation and enhance application startup process

Improve model preloading in PoetryGenerationService with meaningful return value and enhanced error handling

Refactor PoetryGenerationService to streamline model initialization and improve error handling

Refactor model loading to use a consistent model name variable in PoetryGenerationService

Fix variable name for model loading in PoetryGenerationService

Add model preloading functionality to PoetryGenerationService and initialize on startup

Update model name in ModelManager to Llama-3.2-1B-Instruct

Remove optimized module usage from poetry generation service

Update model name in ModelManager to use Llama-1B-Instruct for improved performance

Enhance ModelManager and PoetryGenerationService with optimizations and new features

Fix initialization check in ModelManager to use class variable for singleton pattern

Refactor poetry generation to use singleton ModelManager for model and tokenizer initialization

Set tokenizer's pad token to end-of-sequence token for improved handling

Add initial project structure with FastAPI and poetry generation service