* Improve barcode scanning with native BarcodeDetector
Use the browser-native BarcodeDetector (Shape Detection API) for camera
barcode scanning when available, falling back to html5-qrcode. Native
decoding is hardware-accelerated and far more robust to low light, blur
and small codes than the pure-JS software decoder.
Also:
- Prefer the rear camera and higher resolution for better recognition
- Add a flashlight (torch) toggle for low-light scanning
- Full-frame detection (no aiming box) with multi-code support
- Auto-select a camera so scanning starts without manual selection
- Relax camera constraints (ideal instead of exact) for mobile robustness
- Fix a bug where the native <video> element was not rendered before
scanning started, making the play button unresponsive
* Honor selected camera instead of forcing rear camera
The videoConstraints.facingMode override in the legacy html5-qrcode
path replaced the selected camera ID entirely, so selfie/front cameras
could not be used. Remove the facingMode preference from both scan
paths and rely on the camera selector, which already auto-selects the
rear camera when available.
* Adjust camera input settings for barcode scanning
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Co-authored-by: Matthias Mair <code@mjmair.com>
Co-authored-by: Oliver <oliver.henry.walters@gmail.com>
