Derive callback footer link labels from branding constants

The URLs lived in branding.ts while their display text stayed inline in the
page template, so a rename would have had to touch both. Add matching label
constants and restore the no-external-assets guard to its full strength by
stripping the two intentional footer links before asserting no other
off-machine URL or network call appears.

Author: TheGreatAxios

src/auth/callback-page.test.ts

@@ -1,5 +1,11 @@
 import { describe, expect, test } from "bun:test";
 
+import {
+  PRODUCT_GITHUB_LABEL,
+  PRODUCT_GITHUB_URL,
+  PRODUCT_SITE_LABEL,
+  PRODUCT_SITE_URL,
+} from "../branding.js";
 import { callbackPageHtml, humanizeIdentifier } from "./callback-page.js";
 
 describe("humanizeIdentifier", () => {
@@ -42,19 +48,26 @@ describe("callbackPageHtml", () => {
     );
   });
 
-  test("success footer links to corbits.dev and the GitHub org", () => {
+  test("the footer links to the product site and the GitHub org", () => {
     const html = callbackPageHtml({ subject: "linear" });
-    expect(html).toContain('href="https://corbits.dev"');
-    expect(html).toContain('href="https://github.com/corbitsdev"');
-    expect(html).toContain(">corbits.dev<");
-    expect(html).toContain(">github.com/corbitsdev<");
+    expect(html).toContain(
+      `<a href="${PRODUCT_SITE_URL}">${PRODUCT_SITE_LABEL}</a>`,
+    );
+    expect(html).toContain(
+      `<a href="${PRODUCT_GITHUB_URL}">${PRODUCT_GITHUB_LABEL}</a>`,
+    );
   });
 
   test("the page loads no off-machine assets", () => {
     const html = callbackPageHtml({ subject: "linear" });
-    // Product links in the footer are intentional; nothing else may fetch.
-    expect(html).not.toMatch(/<(?:link|script)\b[^>]+\bsrc=/i);
-    expect(html).not.toMatch(/@import\b/);
-    expect(html).not.toMatch(/url\(\s*["']?https?:/i);
+    // Strip the two intentional footer links, then the page must contain no
+    // other reference to an off-machine URL: no stylesheet/script/image/frame
+    // src or href, no CSS @import or url(), and no script-body network call.
+    const withoutFooterLinks = html.replace(
+      /<a href="https:\/\/[^"]+">[^<]*<\/a>/g,
+      "",
+    );
+    expect(withoutFooterLinks).not.toMatch(/https?:\/\/(?!www\.w3\.org)/);
+    expect(html).not.toMatch(/\b(?:fetch|XMLHttpRequest|WebSocket|sendBeacon)\s*\(/);
   });
 });

src/auth/callback-page.ts

@@ -15,8 +15,10 @@
  */
 
 import {
+  PRODUCT_GITHUB_LABEL,
   PRODUCT_GITHUB_URL,
   PRODUCT_NAME,
+  PRODUCT_SITE_LABEL,
   PRODUCT_SITE_URL,
 } from "../branding.js";
 
@@ -292,7 +294,7 @@ export function callbackPageHtml(page: CallbackPage = {}): string {
     `<h1>${heading}</h1>`,
     `<p class="body">${body}</p>`,
     "<hr>",
-    `<footer>${PRODUCT_NAME}<span class="sep" aria-hidden="true">·</span><a href="${PRODUCT_SITE_URL}">corbits.dev</a><span class="sep" aria-hidden="true">·</span><a href="${PRODUCT_GITHUB_URL}">github.com/corbitsdev</a></footer>`,
+    `<footer>${PRODUCT_NAME}<span class="sep" aria-hidden="true">·</span><a href="${PRODUCT_SITE_URL}">${PRODUCT_SITE_LABEL}</a><span class="sep" aria-hidden="true">·</span><a href="${PRODUCT_GITHUB_URL}">${PRODUCT_GITHUB_LABEL}</a></footer>`,
     "</div>",
     "</main></body>",
     `<script>${SCRIPT}</script>`,

src/branding.ts

@@ -11,9 +11,12 @@ export const PRODUCT_NAME = "Corbits Code";
 // Short attribution form used in compact UI (status lines, footers).
 export const PRODUCT_SHORT_NAME = "Corbits";
 
-// Canonical public URLs shown on the OAuth callback page and other brand surfaces.
+// Canonical public URLs, with the display text that accompanies each, so a link
+// and its label cannot drift apart when a domain or org name changes.
 export const PRODUCT_SITE_URL = "https://corbits.dev";
+export const PRODUCT_SITE_LABEL = "corbits.dev";
 export const PRODUCT_GITHUB_URL = "https://github.com/corbitsdev";
+export const PRODUCT_GITHUB_LABEL = "github.com/corbitsdev";
 
 export const COMMAND_NAME = "corbits";