[Enhancement] Portfolio posts should not appear on the homepage

## What is the main purpose or problem to address? Currently, the homepage of xLog displays content from the Portfolio, which is counterintuitive. There is already a dedicated Portfolio page, so these posts should not appear on the homepage. Although Portfolio items are technically posts, they can be distinguished using tags. ## Additional details <img alt="image1" width="3020" src="https://github.com/user-attachments/assets/6f83986f-f025-47ac-818e-6669e85deaf4" /> ## Assignees No specific assignee needed. ## Type This is an improvement.