fix: handle undefined safeStorage and remove diagnostic logging

Root cause: electron.safeStorage was undefined (not null) when the
property doesn't exist, causing "Cannot read properties of undefined"
error when accessing isEncryptionAvailable.

Fix: Normalize undefined to null with `|| null` operator when importing
safeStorage, ensuring consistent null checks throughout the code.

Changes:
- Set safeStorage to null if electron.safeStorage is undefined
- Remove all diagnostic try-catch blocks from settings UI
- Remove console.log debugging statements
- Restore clean code that now works correctly

This resolves the settings UI crash that prevented the API key
management section from displaying.

src/utils/encryption-utils.ts

@@ -2,7 +2,7 @@
 let safeStorage: any = null;
 try {
 	const electron = require('electron');
-	safeStorage = electron.safeStorage;
+	safeStorage = electron.safeStorage || null;
 } catch (error) {
 	console.warn('Electron safeStorage not available, API keys will be stored in plaintext');
 }