ChatGPT keeps giving me pages router code when I'm on the app router

It's biased toward the older style because there's far more of that code on the internet. Tell it once in a place it keeps:

• Custom instructions / a Project with instructions: "Stack: Next.js 15 App Router, React 19, TypeScript, Supabase via @supabase/ssr. Never use pages/, getServerSideProps, or API routes unless I ask. Prefer Server Components and Server Actions."
• Upload your package.json to the project so versions are in front of it.

And when an answer has pages/ in it, don't fix it in the conversation, regenerate or start a new chat. Once there's old-style code in the context, it keeps copying from itself.

When it matters, paste the relevant page of the official docs into the chat. It'll follow current docs in front of it over old habits from training.