Migrate from window.electron to tauri IPC functions across components

- Replaced `window.electron.invoke` calls with equivalent `tauri` function calls for all IPC interactions.
- Removed `electron.d.ts` TypeScript definitions as they are no longer needed.
- Updated related logic for offline/online state synchronization.
- Added `types.rs` and `shared/mod.rs` modules to support Tauri IPC integration with Rust enums and shared logic.
- Refactored IPC request queues to use updated handler names for consistency with Tauri.

components/offline/OfflineToggle.tsx

@@ -8,7 +8,7 @@ import { faWifi, faCircle } from '@fortawesome/free-solid-svg-icons';
 export default function OfflineToggle() {
     const { offlineMode, toggleOfflineMode } = useContext(OfflineContext);
 
-    if (!window.electron || !offlineMode.isDatabaseInitialized) {
+    if (!offlineMode.isDatabaseInitialized) {
         return null;
     }