Add pre-built panel detection libraries to vendor directory.
These are copied from node_modules during the build process and
included with the application for panel detection functionality.
Included libraries:
- vendor/opencv/opencv.js - OpenCV.js for image processing
- vendor/tfjs/tf.min.js - TensorFlow.js for ML inference
- vendor/coco-ssd/coco-ssd.min.js - COCO-SSD model for object detection
These files enable the panel mode feature in the reader.
Previously, zip.js and fflate were built from the main Foliate repo.
And PDF.js files were copied manually. Now they all build here.
Unfortunately, two CSS files still need to be copied manually.
The fixed-layout renderer now accepts an object for the return value of
`load()` (on the `book.sections` items). If it's an object, the `src`
is the URL of the section, and `onZoom`, if present, will be called
when the viewport is zoomed. With this you can scale the page yourself
rather than relying on the renderer's own scaling with CSS transform.
Also upgraded to PDF.js 4.6.82. And now internal links are broken...
Don't know how to fix that yet.