Add comprehensive wallet testing and fix database export

- Create test-wallet.js for standalone functionality testing
- Fix PaperclipDatabase naming conflict for Node.js compatibility
- Verify Ed25519 key generation, signing, and verification
- Test CLIPS address validation and transaction serialization
- All core crypto functionality working correctly

renderer/paperclip-database.js

@@ -288,9 +288,11 @@ class PaperclipDatabase {
 }
 
 // Create global instance
-const PaperclipDatabase = new PaperclipDatabase();
+const paperclipDB = new PaperclipDatabase();
 
 // Make it available globally
-window.PaperclipDatabase = PaperclipDatabase;
+if (typeof window !== 'undefined') {
+  window.PaperclipDatabase = paperclipDB;
+}
 
-module.exports = PaperclipDatabase;
+module.exports = paperclipDB;