Frontend Upgrade Cycle 1: Infrastructure & Core Stabilization (React 18, Next 14, Node 24)

[fike]

Objective

Stabilize the frontend environment by upgrading the runtime and core framework versions.

Tasks

• Update Dockerfile_frontend_dev to use node:24-slim.
• Upgrade react and react-dom to ^18.3.1.
• Upgrade next to ^14.2.0.
• Run Next.js codemods:
  • npx @next/codemod new-link .
  • npx @next/codemod next-image-to-legacy-image .
• Verify build with yarn build.
• Verify development mode with yarn dev.

Validation

• No build errors.
• Basic navigation and image rendering working as before.