Refactor storage to rename base_dir to upload_folder.

Renamed `base_dir` to `upload_folder` for better clarity and alignment with its purpose. Adjusted references and settings variable to reflect the updated naming convention. This enhances code readability and consistency.

backend/app/core/storage.py

@@ -37,17 +37,17 @@ class StorageProvider(ABC):
 class LocalStorageProvider(StorageProvider):
     """Local filesystem storage provider."""
 
-    def __init__(self, base_dir: str, files_url_path: str):
-        self.base_dir = Path(base_dir)
+    def __init__(self, upload_folder: str, files_url_path: str):
+        self.upload_folder = Path(upload_folder)
         self.files_url_path = files_url_path
 
-        # Ensure base directory exists
-        os.makedirs(self.base_dir, exist_ok=True)
+        # Ensure upload directory exists
+        os.makedirs(self.upload_folder, exist_ok=True)
 
     async def save_file(self, file: UploadFile, destination: str) -> str:
         """Save an uploaded file to the local filesystem."""
         # Ensure destination directory exists
-        dest_path = self.base_dir / destination
+        dest_path = self.upload_folder / destination
         os.makedirs(dest_path.parent, exist_ok=True)
 
         # Save the file
@@ -86,6 +86,6 @@ class LocalStorageProvider(StorageProvider):
 def get_storage_provider() -> StorageProvider:
     """Dependency for getting the configured storage provider."""
     return LocalStorageProvider(
-        base_dir=settings.DATA_FILES_DIR,
+        upload_folder=settings.UPLOAD_FOLDER,
         files_url_path="/files"
     )