Integrate local database management and IPC handlers into Electron

- Add comprehensive IPC handlers for database operations like books, chapters, characters, and conversations.
- Implement local database initialization and user data encryption.
- Update preload script paths for consistent environment handling.
- Modify `page.tsx` to initialize local database within Electron environment.
- Add new dependencies including `node-sqlite3-wasm` and `electron-rebuild`.

tsconfig.electron.json

@@ -20,6 +20,11 @@
     "dist",
     "src",
     ".next",
-    "out"
+    "out",
+    "lib",
+    "components",
+    "app",
+    "context",
+    "electron/preload.ts"
   ]
 }