Setup Flows Auth

# Set Up Flows Authentication

Wire a React app for Flows auth so it can talk to CDF inside Fusion. Two flows exist; pick one based on `app.json`.

## Pick the flow

Read `app.json` if present:

| `app.json` `infra` | Flow | Auth source | Extra package |
|---|---|---|---|
| `"appsApi"` | **Apps API** (new Fusion app host) | `connectToHostApp` from `@cognite/app-sdk` | `@cognite/app-sdk` |
| missing / other | **Classic** (legacy Files API) | `DuneAuthProvider` + `useDune()` from `@cognite/dune` | — |

No `app.json`? Ask the user. Default to **Apps API** — it's the default for `npx @cognite/cli@latest apps create`.

## Step 1 — Read state, decide whether to act

Read `package.json`, `src/main.tsx` (or `src/index.tsx`), `vite.config.ts`, `app.json`.

**A valid setup already exists if any of these is true — in which case do nothing and report no-op:**

- **Classic**: `<DuneAuthProvider>` from `@cognite/dune` wraps `<App />` in the entry file.
- **Apps API, provider pattern**: `<CogniteSdkProvider>` from `@cognite/app-sdk/react` wraps the app (in `App.tsx` or `main.tsx`), and nested components consume the client via `useCogniteSdk()`. Requires `@cognite/app-sdk >= 0.5.1`.

Detect the package manager from the lock file (`pnpm-lock.yaml` → pnpm, `yarn.lock` → yarn, otherwise npm).

## Step 2 — Install missing deps

**Classic flow:**

| Package | Type |
|---|---|
| `@cognite/dune` | runtime |
| `@cognite/sdk` | runtime |
| `@tanstack/react-query` | runtime |
| `vite-plugin-mkcert` | dev |

**Apps API flow:**

| Package | Type |
|---|---|
| `@cognite/app-sdk` | runtime |
| `@cognite/sdk` | runtime |
| `@tanstack/react-query` | runtime |
| `vite-plugin-mkcert` | dev |

Skip anything already in `package.json`. Use the detected package manager (`pnpm add`, `npm install`, `yarn add`; `-D` / `--save-dev` for dev deps).

## Step 3 — Vite config

Add only what's missing. Don't remove existing plugins.

### Classic flow

```ts
import { fusionOpenPlugin } from "@cognite/dune/vite";
import mkcert from "vite-plugin-mkcert";

export default defineConfig({
  base: "./",
  plugins: [react(), mkcert(), fusionOpenPlugin(), /* ... */],
  server: { port: 3001 },
  worker: { format: "es" },
});
```

### Apps API flow

```ts
// or see @cognite/cli/_templates/app/new/config/vite.config.ts.ejs.t source file for newest config
import { fusionOpenPlugin, manifestCspPlugin } from "@cognite/app-sdk/vite";
import mkcert from "vite-plugin-mkcert";

export default defineConfig({
  base: "./",
  // manifestCspPlugin() must be first — its middleware sets the CSP header before any HTML response
  plugins: [manifestCspPlugin(), react(), mkcert(), fusionOpenPlugin(), /* ... */],
  server: { port: 3001 },
  worker: { format: "es" },
});
```

- `base: "./"` — required for Fusion iframe deployment.
- `mkcert()` — provides HTTPS for the dev server (the Fusion parent is HTTPS).
- `fusionOpenPlugin()` — opens the dev URL inside Fusion automatically.
- `manifestCspPlugin()` (Apps API only) — enforces the CSP declared in `manifest.json`; must be first.
- `server.port: 3001` — convention; the plugin falls back to 3001 if no port is set.

## Step 4 — Wire up the entry file and component

### Classic flow

`src/main.tsx`:

```tsx
import { DuneAuthProvider } from "@cognite/dune";
import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
import React from "react";
import ReactDOM from