Fix Pydantic error in Settings class

- Add ClassVar type annotation to DB_DIR field
- Move directory creation logic outside of Settings class
- Update config class to use model_config dict format for Pydantic v2
- Fix database migration error related to non-annotated attribute

app/core/config.py

@@ -1,8 +1,13 @@
 """Application configuration settings."""
 from pathlib import Path
+from typing import ClassVar
 
 from pydantic_settings import BaseSettings
 
+# Create database directory
+DB_DIR = Path("/app") / "storage" / "db"
+DB_DIR.mkdir(parents=True, exist_ok=True)
+
 
 class Settings(BaseSettings):
     """Application settings."""
@@ -12,14 +17,13 @@ class Settings(BaseSettings):
     API_V1_STR: str = "/api/v1"
 
     # Database
-    DB_DIR = Path("/app") / "storage" / "db"
-    DB_DIR.mkdir(parents=True, exist_ok=True)
+    DB_DIR: ClassVar[Path] = DB_DIR
     SQLALCHEMY_DATABASE_URL: str = f"sqlite:///{DB_DIR}/db.sqlite"
 
-    class Config:
-        """Config class for Settings."""
-        case_sensitive = True
-        env_file = ".env"
+    model_config = {
+        "case_sensitive": True,
+        "env_file": ".env",
+    }
 
 
 settings = Settings()