Live view now uses <img :src='streamUrl'> (browser-native MJPEG
support, same as the working test HTML). The fetch-based multipart
parser is kept only for recording frame capture. Also fixed
multipart boundary parsing to correctly handle boundary values
that already include leading dashes.
- LiveView receives streamUrl string, passes it directly to <img>
- useMjpegStream simplified to URL + state management
- useRecorder manages its own fetch stream independently
- RecorderControls shows recorder-specific errors