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/OfflinePinSetup.tsx

@@ -5,6 +5,7 @@ import { SessionContext } from '@/context/SessionContext';
 import { useTranslations } from 'next-intl';
 import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';
 import { faLock, faShieldAlt, faEye, faEyeSlash } from '@fortawesome/free-solid-svg-icons';
+import * as tauri from '@/lib/tauri';
 
 interface OfflinePinSetupProps {
   onClose?: () => void;
@@ -53,15 +54,13 @@ export default function OfflinePinSetup({ onClose, onSuccess, showOnFirstLogin }
     setError('');
 
     try {
-      if (window.electron) {
-        const result = await window.electron.offlinePinSet(pin);
+      const result = await tauri.offlinePinSet(pin);
 
-        if (result.success) {
-          await window.electron.offlineModeSet(true, 30); // 30 days sync interval
-          onSuccess?.();
-        } else {
-          setError(result.error || t('offline.pin.errors.setupFailed'));
-        }
+      if (result.success) {
+        await tauri.offlineModeSet(true, 30);
+        onSuccess?.();
+      } else {
+        setError(result.error || t('offline.pin.errors.setupFailed'));
       }
     } catch (error) {
       console.error('[OfflinePin] Error setting PIN:', error);