Extension paths

Like pi’s extensions/skills/themes: compose at the edges. Do not fork the hub to change a bubble.

Supported paths (prefer in order)

1. Message plugins — custom render for a role or custom type → Message plugins
2. Theme — light/dark and tokens → Themes
3. UI chrome — sidebar, status bar, palette labels, layout → UI chrome
4. New API capability — hub method + route + client → Server API

Always re-read Change boundaries if unsure.

Anti-patterns

• Replacing SSE with WebSockets “for simplicity”
• Adding Express / tRPC / socket.io
• Duplicating model/auth config outside pi
• Vendoring a second UI kit beside web/src/lib/kit
• Wide refactors of hub.js / chat-stream.ts for a feature request

After you change code

npm test                 # stream + server contracts
npm run check            # Svelte and TypeScript checks
npm run build            # dist/ for prod / git install