Remove SyncService and introduce context-based offline mode and state management

- Delete `SyncService` and its associated bidirectional synchronization logic.
- Add multiple context providers (`OfflineProvider`, `AlertProvider`, `LangContext`, `UserContext`, `SessionContext`, `WorldContext`, `SettingBookContext`) for contextual state management.
- Implement `SecureStorage` for OS-level secure data encryption and replace dependency on `SyncService` synchronization.
- Update localization files (`en.json`, `fr.json`) with offline mode and error-related strings.

context/SettingBookContext.ts

@@ -0,0 +1,12 @@
+import {Context, createContext, Dispatch, SetStateAction} from "react";
+
+export interface SettingBookContextProps {
+    bookSettingId: string;
+    setBookSettingId: Dispatch<SetStateAction<string>>
+}
+
+export const SettingBookContext: Context<SettingBookContextProps> = createContext<SettingBookContextProps>({
+    bookSettingId: '',
+    setBookSettingId: (): void => {
+    }
+})