nextjs upgrades & security patch

[ElishaKay]

Ready for merge 👍

• Fixed issue of websocket connection dying midsession when user tries to chat with report
• Fixed the issue of only the first reportBlock being shown to user - instead, only the final reportBlock is shown to the user - thereby making the reflection & revision process of the multi_agents flow more transparent to the user
• Fixed the issue of duplicate sourceBlocks shown to user
• consolidate multiple sourceBlocks and reportBlocks into 1 sourceBlock and 1 reportBlock
• toggle images in report with left & right buttons on desktop or swiping left & right on mobile
• Removed the getConfig & setConfig routes, and the "API Variables" tab on the frontend - until we think through how to restrict access to those routes

Notes: keeping websocket connection alive with continuous ping-pong game between frontend and backend