2.9.15: App backup/restore, translation book sort fix

2.9.15

App Backup & Restore

Full app data backup and restore, accessible from the home page menu (⋮ → Backup data / Restore data).

Backup

• Creates a ZIP of the entire app data directory — Hive preferences, Isar database, ッツ reader IndexedDB (imported books, reading positions, bookmarks), shared preferences, and all other app state
• Saves to /storage/emulated/0/tmp/ with filename format: shiroikumanojidoujishodainihan_backup_2026-04-19_14-30-25.zip
• Progress dialog with spinner shown during backup creation
• Completion dialog displays file path with a Share button to send the backup to cloud storage, file managers, etc.
• Skips transient data: cache, code_cache, dictionaryImportWorkingDirectory

Restore

• File picker filtered to .zip files
• Confirmation dialog warns that all current data will be replaced and the app will close
• Progress dialog shown during restore
• After restore completes, the app exits and reinitializes with the restored data on next launch
• Backward-compatible with older backup formats

Translation Book Sort Order Fix

• Translation books (titles containing ⇨) now have their lastBookOpen reset to 0 on every interaction in the secondary WebView, not just at import time
• Prevents translation books from floating to the top of the book list after page turns or scrolling in the split view