MediaImporter streams URL imports via wp_safe_remote_get with limit_response_size,
checks Content-Length, intersects the MIME whitelist with get_allowed_mime_types and
validates real content; base64 is size-checked before decoding. Server-side failures
are write_failed; a failed alt text deletes the new attachment again (or partial_write).
MediaUploads is the shared permission/result helper of both upload abilities.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7
