- Remove dead structs: ReadingProgress, HomeData, PBList (Models.swift)
- Remove unused APIClient members: fetchRaw, setSessionId, BrowseParams; simplify logout(); drop no-op CodingKeys from BrowseResponse
- Remove absolutePrevChapter/absoluteNextChapter computed props (replaced by prevChapter/nextChapter); replace URLSession cover prefetch with Kingfisher
- Drop scrollOffset state var and dead subtitle block in ChapterRow (BookDetailView)
- Remove never-set chaptersLoading published prop (BookDetailViewModel)
- Add unified ChipButton(.filled/.outlined) to CommonViews replacing three near-identical pill chip types
- Replace FilterChipView+SortChip in LibraryView and FilterChip in BrowseView with ChipButton
- Replace inline KFImage usage in HomeView with AsyncCoverImage
- Fix deprecated .navigationBarHidden(true) → .toolbar(.hidden, for: .navigationBar) in AuthView
