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.preload.json

@@ -1,11 +1,20 @@
 {
-  "extends": "./tsconfig.electron.json",
   "compilerOptions": {
     "module": "CommonJS",
     "moduleResolution": "node",
-    "outDir": "dist/electron"
+    "target": "ES2022",
+    "outDir": "dist/electron",
+    "lib": ["ES2022"],
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "strict": true,
+    "resolveJsonModule": true,
+    "noEmit": false
   },
   "include": [
     "electron/preload.ts"
+  ],
+  "exclude": [
+    "node_modules"
   ]
 }