feat(rust): scaffold Rust workspace and fix TypeScript build errors

- Add @git.zone/tsrust with linux_amd64/linux_arm64 cross-compilation
- Scaffold Rust workspace with 5 crates: mailer-core, mailer-smtp, mailer-security, mailer-napi, mailer-bin
- Fix all TypeScript compilation errors for upgraded dependencies (smartfile v13, mailauth v4.13, smartproxy v23)
- Replace smartfile.fs/memory with @push.rocks/smartfs throughout codebase
- Fix .ts import extensions to .js for NodeNext module resolution
- Update DKIMSignOptions usage to match mailauth v4.13 API
- Add MTA error classes with permissive signatures for legacy SMTP client
- Replace removed DcRouter/StorageManager/deliverability imports with local interfaces

ts/mail/delivery/smtpclient/utils/logging.ts

@@ -3,8 +3,8 @@
  * Client-side logging utilities for SMTP operations
  */
 
-import { logger } from '../../../../logger.ts';
-import type { ISmtpResponse, ISmtpClientOptions } from '../interfaces.ts';
+import { logger } from '../../../../logger.js';
+import type { ISmtpResponse, ISmtpClientOptions } from '../interfaces.js';
 
 export interface ISmtpClientLogData {
   component: string;