feat: Implement OAuth2 authentication with Google and GitHub

- Added OAuth2 endpoints for Google and GitHub authentication.
- Created OAuth service to handle provider interactions and user info retrieval.
- Implemented user OAuth repository for managing user OAuth links in the database.
- Updated auth service to support linking existing users and creating new users via OAuth.
- Added CORS middleware to allow frontend access.
- Created tests for OAuth endpoints and service functionality.
- Introduced environment configuration for OAuth client IDs and secrets.
- Added logging for OAuth operations and error handling.

app/core/config.py

@@ -13,13 +13,16 @@ class Settings(BaseSettings):
         extra="ignore",
     )
 
+    # Application Configuration
     HOST: str = "localhost"
     PORT: int = 8000
     RELOAD: bool = True
 
+    # Database Configuration
     DATABASE_URL: str = "sqlite+aiosqlite:///data/soundboard.db"
     DATABASE_ECHO: bool = False
 
+    # Logging Configuration
     LOG_LEVEL: str = "info"
     LOG_FILE: str = "logs/app.log"
     LOG_MAX_SIZE: int = 10 * 1024 * 1024
@@ -31,12 +34,19 @@ class Settings(BaseSettings):
         "your-secret-key-change-in-production"  # noqa: S105 default value if none set in .env
     )
     JWT_ALGORITHM: str = "HS256"
-    JWT_ACCESS_TOKEN_EXPIRE_MINUTES: int = 15  # Shorter-lived access token
-    JWT_REFRESH_TOKEN_EXPIRE_DAYS: int = 7  # Longer-lived refresh token
+    JWT_ACCESS_TOKEN_EXPIRE_MINUTES: int = 15
+    JWT_REFRESH_TOKEN_EXPIRE_DAYS: int = 7
 
     # Cookie Configuration
-    COOKIE_SECURE: bool = True  # Set to False for development without HTTPS
+    COOKIE_SECURE: bool = True
     COOKIE_SAMESITE: Literal["strict", "lax", "none"] = "lax"
 
+    # OAuth2 Configuration
+    GOOGLE_CLIENT_ID: str = ""
+    GOOGLE_CLIENT_SECRET: str = ""
+    GITHUB_CLIENT_ID: str = ""
+    GITHUB_CLIENT_SECRET: str = ""
+    OAUTH_REDIRECT_URL: str = "http://localhost:8001/auth/callback"
+
 
 settings = Settings()