Proposal: Client notification system

[terrablue]

Problem

Client-side code (form submissions, navigation, async actions) can encounter errors that are not tied to any specific UI component — network failures, server errors, session expiry. Currently there is no way to surface these app-wide.

Proposed API

A simple event-bus on client:

client.notify(message: string, level?: "info" | "warn" | "error")

Any client-side code can call it. The root layout subscribes and renders notifications however the app wants — toast, banner, overlay.

Subscription side (in root layout component):

client.on("notify", (message, level) => {
  // push to local notification state
});

Integration points

• createForm calls client.notify(...) on network error instead of setErrors
• boot.ts global submit/navigate error handlers call it too
• Primate users can call it from their own route handlers or components

Non-goals

• No built-in UI — Primate provides the mechanism, the app owns the rendering
• No persistence — notifications are ephemeral, in-memory only

Actionables

1. Implement client.notify / client.on event bus in client/index.ts
2. Update createForm and boot.ts to use it
3. Add example notification component to docs