feat: Inter + JetBrains Mono typography for premium AI product feel

[CodeBuildder]

Summary

• Replace global UI typography with Inter for product text and JetBrains Mono for code/metadata
• Apply Inter to the app shell and Threat Feed card/detail content
• Apply JetBrains Mono to tags, timestamps, confidence metadata, and section titles
• Tune AI assessment, false positive, confidence, and blast radius typography for readability

Checks

• npm run build passed
• Vite emitted a non-blocking warning that CSS @import conventionally precedes @tailwind statements; index.css order matches the requested replacement