Emails with multipart/related structure reference embedded images via
cid: URIs. The WebView's CSP only allows data:/blob: sources, so those
images were never shown. injectInlineImages() now replaces each cid:
reference with a data: URI using the decoded bytes from the MIME tree,
both for double-quoted and single-quoted src attributes.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>