davidchtchian bolts a French UI onto Mike

davidchtchian wires up next-intl (a standard library for translating Next.js apps) and sets Mike up to serve English, German, and French. The first commit lays the scaffolding; the second corrects course and moves every page under a locale-aware URL structure, which is the conventional shape for this kind of work.

The translation itself is shallow - navigation, sign-in, and a language switcher are localised, but actual page content and even the generic error screen are still hardcoded English. The same commit also quietly bundles two unrelated features: a new Mistral model provider (the French AI lab) plumbed end-to-end, and a pair of chat toggles for legal sources and citation style. Both look half-finished on a close read.