feat: enhance GenericVerifiableCredential interface with explicit optional properties

- Add name, description, and agent as optional properties to GenericVerifiableCredential
- Improve type safety and IntelliSense for common claim properties
- Maintain backward compatibility with existing code
- Reduce need for type assertions when accessing claim properties

doc/migration-to-wa-sqlite.md

@@ -69,8 +69,8 @@ export async function migrateActiveDid(): Promise<MigrationResult> {
   
   // 3. Update SQLite master settings
   await updateDefaultSettings({ activeDid: dexieActiveDid });
-}
-```
+   }
+   ```
 
 #### Enhanced `migrateSettings()` Function
 The settings migration now includes activeDid handling:
@@ -171,7 +171,7 @@ npm run test:migration
 ```
 
 ### ActiveDid Testing
-```typescript
+   ```typescript
 // Test activeDid migration specifically
 const result = await migrateActiveDid();
 expect(result.success).toBe(true);
@@ -204,7 +204,7 @@ logger.setLevel('debug');
 // Check migration status
 const comparison = await compareDatabases();
 console.log('Settings differences:', comparison.differences.settings);
-```
+   ```
 
 ## Future Enhancements