Inline CID images were replaced with raw JMAP download URLs that require authentication. When the browser loaded these as <img src>, the server responded with WWW-Authenticate: Basic, triggering a native login popup.
- Add fetchBlobAsObjectUrl() to JMAPClient that fetches blobs via authenticated request and returns blob: object URLs
- Update email-viewer and thread-conversation-view to fetch CID images asynchronously with auth, using blob: URLs instead of raw server URLs
- Add ALLOWED_URI_REGEXP to DOMPurify config so blob: URLs are not stripped during sanitization
- Add tests for fetchBlobAsObjectUrl and CID/blob URL sanitization
Linus Rath