- Remove hard-coded PROD_SHARE_DOMAIN from src/constants/app.ts
- Update all sharing functionality to use environment-specific APP_SERVER
- Rewrite domain configuration documentation to reflect unified approach
- Simplify domain management with single APP_SERVER constant
- Update README.md examples to use APP_SERVER for all URL generation
This change eliminates the complexity of separate constants for different
URL types and provides consistent environment-specific configuration for
all functionality including sharing.