Allow Playwright tests to be authenticated

The `GH_TOKEN` environment variable can be used both locally and in CI
to avoid testing the GitHub OAuth flow (which is provided by the Octokit
library and can therefore be assumed to be well tested).

In local development the token can be retrieved by logging into Towtruck
and then copying the value of the `Token` cookie.

In CI, the correct value is automatically populated by GitHub Actions
into a secret.

.github/workflows/playwright.yml

@@ -30,6 +30,7 @@ jobs:
           CLIENT_SECRET: ${{ secrets.CLIENT_SECRET }}
           WEBHOOK_SECRET: ${{ secrets.WEBHOOK_SECRET }}
           REDIRECT_URL_BASE: ${{ secrets.REDIRECT_URL_BASE }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       - uses: actions/upload-artifact@v4
         if: always()
         with:

e2es/towtruck.spec.js

@@ -1,11 +1,22 @@
 import { test, expect } from "@playwright/test";
 
-test("has dependency info", async ({ page, baseURL }) => {
+test("has dependency info", async ({ page, context, baseURL }) => {
+  await context.addCookies([{
+    name: "Token",
+    domain: "127.0.0.1",
+    path: "/",
+    value: process.env.GH_TOKEN,
+  }]);
+
   await page.goto(baseURL);
 
   await expect(page).toHaveTitle(/Towtruck/);
 
-  page.getByText("There are 3 repositories that Towtruck is tracking for dxw.");
+  expect(await page.getByText("There is 1 organisation using Towtruck that you are a member of.").count()).toBe(1);
+
+  await page.getByRole("link", { name: "dxw", exact: true }).click();
+
+  expect(await page.getByText("There are 3 repositories that Towtruck is tracking for dxw.").count()).toBe(1);
 
   const tableHeadings = [
     "Name",