fix(mail/delivery): Centralize runtime/plugin imports and switch modules to use plugins exports; unify EventEmitter usage; update Deno dependencies and small path/server refactors

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@serve.zone/mailer',
-  version: '1.2.0',
+  version: '1.2.1',
   description: 'Enterprise mail server with SMTP, HTTP API, and DNS management - built for serve.zone infrastructure'
 }