Goal
Google Chrome sends a reduced user agent header (see T242825: Deal with Google Chrome User-Agent deprecation for more context). This impacts the work of CheckUsers who rely on detailed user agent header in detecting sockpuppets. After talking to Legal, Trust&Safety and stewards, the desired way forward is to continue to get the user-agent data from Chrome, per Chrome's proposed Client-Hints standard. The standard is not yet implemented by Firefox or Safari. Mozilla's position on the standard is "neutral".
Acceptance criteria
- Extension:CheckUser stores and displays high entropy client-hint data, similarly to how it currently stores and displays user agent data
- Extension:CheckUser stores client hint header data for specific actions (form edit) | T258105: Implement storage for User-Agent Client Hints header data
- Extension:CheckUser deletes high-entropy client hint header data after 90 days | T337943: Update maintenance/purgeOldData to remove client hint data T340959: Update CheckUser prune job to remove client hint data
- Extension:CheckUser displays client hint header data | T337942: Display client hint data
- MediaWiki requests client hint header for web and API entrypoints that CheckUser needs to log (edit) | T337944: Implement support for requesting client hint header