Refactor file URL handling to use relative paths.

Updated file URL generation to return relative paths instead of absolute paths, ensuring better portability and consistency. Adjusted relevant methods to compute paths relative to the base directory.

backend/app/core/storage.py

@@ -79,15 +79,18 @@ class LocalStorageProvider(StorageProvider):
         # The upload URL is to our custom upload endpoint
         upload_url = f"{settings.API_VERSION_STR}/uploads/{token}"
 
-        # The file URL is where the file will be accessible after upload
-        file_url = f"{self.upload_folder}/{file_path}"
+        # Return just the relative path
+        upload_folder_relative = os.path.relpath(self.upload_folder, settings.DATA_FILES_DIR)
+        file_url = f"{upload_folder_relative}/{file_path}"
 
         return upload_url, file_url
 
     def get_uploaded_file_url(self, file_path: str) -> str:
         """Get the URL for accessing a file."""
-        return f"{self.upload_folder}/{file_path}"
+        upload_folder_relative = os.path.relpath(self.upload_folder, settings.DATA_FILES_DIR)
+        return f"{upload_folder_relative}/{file_path}"
 
     def get_file_url(self, file_path: str) -> str:
         """Get the URL for accessing a file."""
-        return f"{self.files_url_path}/{file_path}"
+        # Return just the relative path
+        return file_path