Add offline mode logic for main chapters and refine IPC handlers

- Integrate `OfflineContext` into `MainChapter` and related components to handle offline scenarios for chapter operations.
- Add conditional logic to toggle between server API requests and offline IPC handlers (`db:chapter:add`, `db:chapter:remove`).
- Extend `GET /book/story` endpoint to include `mainChapter` data.
- Refactor IPC handlers for chapters to accept structured data arguments with stricter typings.
- Update frontend key assignments for `BookList` component for improved rendering stability.

components/book/BookList.tsx

@@ -253,8 +253,8 @@ export default function BookList() {
                                     <div
                                         className="flex justify-between items-center w-full max-w-5xl mx-auto mb-6 px-6">
                                         <h2 className="text-3xl text-text-primary capitalize font-['ADLaM_Display'] flex items-center gap-3">
-                                            <span key="icon" className="w-1 h-8 bg-primary rounded-full"></span>
-                                            <span key="title">{category}</span>
+                                            <span className="w-1 h-8 bg-primary rounded-full"></span>
+                                            <span>{category}</span>
                                         </h2>
                                         <span
                                             className="text-muted text-lg font-medium bg-secondary/30 px-4 py-1.5 rounded-full">{books.length} {t("bookList.works")}</span>
@@ -263,7 +263,7 @@ export default function BookList() {
                                     <div className="flex flex-wrap justify-center items-start w-full px-4">
                                         {
                                             books.map((book: BookProps, idx) => (
-                                                <div key={book.bookId}
+                                                <div key={book.bookId || `book-${idx}`}
                                                      {...(idx === 0 && {'data-guide': 'book-card'})}
                                                      className={`w-full sm:w-1/3 md:w-1/4 lg:w-1/5 xl:w-1/6 p-2 box-border ${User.guideTourDone(session.user?.guideTour || [], 'new-first-book') && 'mb-[200px]'}`}>
                                                     <BookCard book={book}