Add Windows client hint brands override to match header we override natively

[laghee]

Asana Task/Github Issue: https://app.asana.com/1/137249556945/project/72649045549333/task/1208581002806545?focus=true

Description

Adding an override for our client hints brands in the JS API to match those we send in the Sec-CH-UA header and resolve breakage caused by current inconsistency between the two.

Testing Steps

Use privacy test page (https://github.com/duckduckgo/privacy-test-pages/pull/356) on WebView2 build from this branch of C-S-S OR Manually compare Sec-Ch-Ua header brands with output of navigator.userAgentData.brands and navigator.userAgentData.getHighEntropyValues(['brands'])

Checklist

Please tick all that apply:

• [x] I have tested this change locally
• [x] I have tested this change locally in all supported browsers
• [ ] This change will be visible to users
• [x] I have added automated tests that cover this change
• [x] I have ensured the change is gated by config
• [ ] This change was covered by a ship review
• [x] This change was covered by a tech design
• [ ] Any dependent config has been merged

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[!NOTE] Introduces uaChBrands to override navigator.userAgentData brands to match Sec-CH-UA (with domain-specific overrides) and adds Playwright integration tests.

• Feature: uaChBrands
  • Intercepts navigator.userAgentData to override brands and getHighEntropyValues/fullVersionList outputs to align with Sec-CH-UA.
  • Filters out "Microsoft Edge WebView2", replaces "Microsoft Edge" with target brand (default "DuckDuckGo"), or appends target brand using Chromium version.
  • Supports domain-scoped overrides via settings.domains (e.g., per-domain brand like "Netscape Navigator").
  • Enabled in Windows platform via injected/src/features.js.
• Tests
  • New Playwright spec integration-test/ua-ch-brands.spec.js covering default and domain-specific overrides.
  • Test pages under integration-test/test-pages/ua-ch-brands/** validate brands and fullVersionList mutations.
  • Playwright config updated to include the new spec for the windows project.

^{Written by Cursor Bugbot for commit 651637f2012cd74e40e980ca1295dba48a24f260. This will update automatically on new commits. Configure here.}

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• To see the specific tasks where the Asana app for GitHub is being used, see below:
  • https://app.asana.com/0/0/1212017506660681

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[github-actions[bot]]

Temporary Branch Update

The temporary branch has been updated with the latest changes. Below are the details:

• Branch Name: pr-releases/pr-2028
• Commit Hash: c9195bef41098400018ab9182a1b8b9eb90029e8
• Last Updated: November 27, 2025 at 4:06:12 PM UTC
• Install Command: npm i github:duckduckgo/content-scope-scripts#c9195bef41098400018ab9182a1b8b9eb90029e8

Please use the above install command to update to the latest version.

[github-actions[bot]]

[Beta] Generated file diff

Time updated: Thu, 27 Nov 2025 16:06:27 GMT

Android

    - android/adsjsContentScope.js

• android/autofillImport.js
• android/brokerProtection.js
• android/contentScope.js

File has changed

Apple

    - apple/contentScope.js

• apple/contentScopeIsolated.js

File has changed

Chrome-mv3

    - chrome-mv3/inject.js

File has changed

Firefox

    - firefox/inject.js

File has changed

Integration

    - integration/contentScope.js

File has changed

Windows

    - windows/contentScope.js

File has changed