feat(storage): add comprehensive tests for StorageManager with memory, filesystem, and custom function backends

feat(email): implement EmailSendJob class for robust email delivery with retry logic and MX record resolution

feat(mail): restructure mail module exports for simplified access to core and delivery functionalities

ts/mail/core/classes.templatemanager.ts

@@ -291,7 +291,7 @@ export class TemplateManager {
       
       // Get all JSON files
       const files = plugins.fs.readdirSync(directory)
-        .filter(file => file.endsWith('.tson'));
+        .filter(file => file.endsWith('.json'));
       
       for (const file of files) {
         try {