chore(deps): patch Next.js and sharp in RAG UI

[santoshkumarradha]

Summary

• bump Next.js from 15.5.22 to 15.5.25
• bump the sharp override from 0.35.3 to 0.35.4
• clear the current critical Next.js and high-severity sharp advisories for the RAG evaluation UI

Validation

• npm ci
• npm audit --omit=dev (0 vulnerabilities)
• npm run build

[santoshkumarradha]

Superseded by #1055, which includes these Next.js and sharp fixes together with the remaining open security updates and has green required checks.