Add Splitwise clone backend

app/config.py

@@ -0,0 +1,18 @@
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+
+class Settings(BaseSettings):
+    model_config = SettingsConfigDict(env_file=".env", env_file_encoding="utf-8")
+
+    database_url: str = "postgres://spliteasy:spliteasy@localhost:5432/spliteasy"
+    oidc_issuer: str = "https://keycloak.example.com/realms/myrealm"
+    oidc_client_id: str = "spliteasy"
+    oidc_client_secret: str = ""
+    allowed_audiences: str = "account,spliteasy"
+
+    @property
+    def audiences(self) -> list[str]:
+        return [a.strip() for a in self.allowed_audiences.split(",") if a.strip()]
+
+
+settings = Settings()