v2.3.5

A round of quality-of-life improvements: dark mode, easier category management, refreshed Chinese translations, and fixes from community feedback (#169).

✨ New

• Dark / light theme toggle: switch themes from a toggle next to skip during onboarding, or press D anytime in the app. It's also listed in the keyboard shortcuts panel (?).
• Edit categories in place: rename or recolor a category from Settings without rebuilding it. Recolors apply to existing milestones automatically.
• Select All / Select None when choosing a chapter's milestones, handy for densely packed timelines.

🐛 Fixes

• Categories are now included in backups and restored correctly, so custom categories no longer revert to defaults after restoring from a file.
• WATCH-mode notes wrap properly again: multi-line notes keep their line breaks instead of running together, and the timestamp now sits above the note for a cleaner layout.

🌐 Translations

• Refreshed Simplified Chinese (zh_CN): corrected Traditional/Taiwan vocabulary that had leaked in, with more natural phrasing throughout.
• Traditional Chinese is now served consistently from the Hong Kong (zh_HK) translations.
• New keyboard shortcut and chapter strings translated across all supported languages.

Thanks to @win2ter for the Chinese translation contributions (#161) and the detailed reports in #169.

Coming next: locale-aware date ordering and additional translation polish.