Add style detection and model matching for auto mode

Style Detection (detect_generation_type):
- Detects 9 artistic styles: anime, photorealistic, digital_art, cgi, cartoon, fantasy, traditional, scifi, horror
- Extracts style keywords from prompts for matching
- Returns style info in generation type dict

Style Matching (select_best_model):
- Matches LoRA adapters to requested style (+60 bonus for style match)
- Matches base models to requested style (+50 bonus for style match)
- Checks model name, ID, and tags for style indicators
- Examples:
  - 'anime girl' → selects anime-optimized models/LoRAs
  - 'photorealistic portrait' → selects realism models
  - 'cyberpunk city' → selects sci-fi models/LoRAs

This allows --auto mode to intelligently select models based on
the artistic style requested in the prompt.