Fix quirky pagination and sorting behavior in /user/resources endpoint

[saurabh12nxf]

Change(s)

Change Type: Fixed

Change Category: Internal

Changelog Entry: Fixed quirky pagination and sorting behavior in /user/resources endpoint.

The /user/resources endpoint previously had unintuitive behavior where it would paginate at the AIoDEntry level, then re-query individual asset tables (potentially reordering results), and finally re-sort in Python. This fix preserves the database sort order throughout the query process by creating an entry_order mapping and applying it when fetching assets from individual tables, eliminating the need for Python-level re-sorting.

How to Test

1. Create multiple resources (publications, datasets, etc.) with different date_modified timestamps
2. Query /user/resources with pagination and sorting parameters:
   • GET /user/resources?limit=5&sort=date_modified&direction=desc
   • GET /user/resources?limit=5&offset=5&sort=date_modified&direction=desc
3. Verify that:
   • Results are sorted correctly by date_modified
   • Pagination maintains the sort order across pages
   • Multiple asset types are each sorted correctly

Existing tests in test_user_endpoints.py should pass (note: local Windows environment has unrelated test infrastructure issues with SQLite temp files, but CI/CD should pass).

Checklist

• Tests have been added or updated to reflect the changes, or their absence is explicitly explained.
• Documentation has been added or updated to reflect the changes, or their absence is explicitly explained.
• A self-review has been conducted checking:
  • No unintended changes have been committed.
  • The changes in isolation seem reasonable.
  • Anything that may be odd or unintuitive is provided with a GitHub comment explaining it (but consider if this should not be a code comment or in the documentation instead).
• All CI checks pass before pinging a reviewer, or provide an explanation if they do not.
• The PR title matches the changelog entry's one-line description.

Related Issues

Closes #654