Version 1.7 sent to AppStore

[petrjahoda]

Version 1.7 [19.3 sent to Apple Store]

New Features:
- Red underline highlight style (6th color option)
- Bulk book selection for assigning collections in the library
- Per-book reading statistics: accessible from the book Details sheet and a new Stats sheet inside the reader (daily reading chart, consistency score, longest session)

Improvements/Fixes:
- Cloud sync icon now only appears while actively syncing
- Highlights icon shown directly in the toolbar on iPad (instead of buried in ellipsis menu)
- Library statistics sheet simplified, now includes collections count
- "Select" option moved into the iPad ellipsis menu (above "Change library")
- Better tap targets: increased bottom toolbar icon font size
- Accessibility labels added to book stats loading and stat rows

Localization:
- Added missing translations for bulk selection and book statistics strings across all 15 languages