[bugfix]Adapt the method of writing objects to the database.

[Potterluo]

Title: Enhance Result-Capturing Decorator to Handle Both Single Objects and Lists

Description:

This PR improves the logic of the result-capturing decorator (used in proj_process) to correctly handle two common return patterns:

• A single result object (e.g., a dictionary, dataclass instance, or custom object)
• A list of result objects

Previously, the decorator assumed _proj always contained a list. Passing a single object would cause unexpected iteration (e.g., over dictionary keys) or runtime errors.

Changes:

• Added _ensure_list() utility to normalize input: wraps non-list inputs into a single-item list while preserving actual lists.
• Enhanced _to_dict() to safely convert common object types (dicts, dataclasses, namedtuples, and regular objects with __dict__) into dictionaries.
• Updated proj_process to use these utilities, ensuring robust ingestion into the database regardless of whether the source returns one item or many.
• Improved error messages for clearer debugging when conversion fails.

Test: