Source Cleanup — cognition / lotteon-tech Discontinued, langchain-blog Updated

Some source operations have been adjusted due to circumstances on the original source side.

• Discontinued: cognition (RSS endpoint removed, no longer being collected), lotteon-tech (collection disabled due to changes in the site's bot-blocking policy).
• URL Update: The langchain-blog feed address has moved to a new location, and collection of new posts has resumed normally.

Existing posts from discontinued sources remain available for search and viewing.