Add classic eye image assets and import scripts
- Generate 18 classic eye variants in 3 styles (realistic, anime, cartoon)
with 6 colors each (blue, green, brown, hazel, grey, amber)
- Add scripts for generating, converting, and importing eyes:
- generate_classic_eyes_ppm.py: Generate PPM images (no dependencies)
- download_classic_eyes.py: Full-featured generator with PIL
- startup_import_eyes.py: Import eyes on backend startup
- import_saved_eyes.py: Import from saved directory
- Update docker-compose to mount scripts directory
- Include metadata.json for tracking eye properties