Fix "NotSupportedError: The element has no supported sources" when using HTMLAudioElement
or HTMLVideoElement with Base64 data URLs. Use when: (1) audio/video from localStorage or
APIs fails to play, (2) data: URLs as src cause browser compatibility issues, (3) mobile
Safari refuses to load media. Covers fetch + URL.createObjectURL pattern for better browser
support, especially for localStorage persistence and file uploads.