Initial commit: CLEAN architecture foundation for fantasy hockey backend

Implemented CLEAN architecture with clear separation of concerns:
- Domain layer with entities (Player, Team, Stats, FantasyTeam) and repository interfaces
- Application layer with use case implementations
- Infrastructure layer with NHL API and Yahoo Fantasy API adapters
- Presentation layer with FastAPI configuration and dependency injection

Key features:
- Swappable data source adapters (NHL API, Yahoo Fantasy API)
- Repository pattern for data access abstraction
- Dependency injection for loose coupling
- FastAPI framework with async support
- PostgreSQL database configuration
- Environment-based configuration management

Technology stack: Python 3.11+, FastAPI, PostgreSQL, nhl-api-py, yfpy

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/infrastructure/config/settings.py

@@ -0,0 +1,33 @@
+"""Application configuration settings."""
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+
+class Settings(BaseSettings):
+    """Application settings loaded from environment variables."""
+
+    model_config = SettingsConfigDict(
+        env_file=".env",
+        env_file_encoding="utf-8",
+        case_sensitive=False,
+    )
+
+    # Application
+    app_name: str = "Project Kempe - Fantasy Hockey Backend"
+    app_version: str = "0.1.0"
+    debug: bool = False
+
+    # Database
+    database_url: str = "postgresql+asyncpg://user:password@localhost:5432/fantasy_hockey"
+
+    # Yahoo Fantasy API
+    yahoo_consumer_key: str = ""
+    yahoo_consumer_secret: str = ""
+
+    # API Configuration
+    api_prefix: str = "/api/v1"
+    cors_origins: list[str] = ["http://localhost:3000"]
+
+
+def get_settings() -> Settings:
+    """Returns the application settings singleton."""
+    return Settings()