web: Fix off-by-one bug in page switching logic
workflow: Emit signal when capture failed
workflow: Wait for ongoing captures to finish before finishing
workflow: Fix up imports
tesseract: Make language-detection more robust
web: Only crop pages on unmount if cropping is active
web: Disable waiting overlay when an error occurs during capture
web: Fix order of preview images in capture screen

Previously we had ['odd', 'even'], but ['even', 'odd'] is the natural
order from the bookspread.
web: Display error box for unspecified backend errors
discovery: Add SO_REUSEADDR option for socket to fix auto-reloading
web: Fix typo in error handler for non-retrievable pages
web: Shorten navbar titles
web: Fix zip caption for non-OSX
web: Preparation callback