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/smtpserver/security-handler.ts

@@ -4,14 +4,14 @@
  * email validation, and authentication
  */
 
-import * as plugins from '../../../plugins.ts';
-import type { ISmtpSession, ISmtpAuth } from './interfaces.ts';
-import type { ISecurityHandler, ISmtpServer } from './interfaces.ts';
-import { SmtpLogger } from './utils/logging.ts';
-import { SecurityEventType, SecurityLogLevel } from './constants.ts';
-import { isValidEmail } from './utils/validation.ts';
-import { getSocketDetails, getTlsDetails } from './utils/helpers.ts';
-import { IPReputationChecker } from '../../../security/classes.ipreputationchecker.ts';
+import * as plugins from '../../../plugins.js';
+import type { ISmtpSession, ISmtpAuth } from './interfaces.js';
+import type { ISecurityHandler, ISmtpServer } from './interfaces.js';
+import { SmtpLogger } from './utils/logging.js';
+import { SecurityEventType, SecurityLogLevel } from './constants.js';
+import { isValidEmail } from './utils/validation.js';
+import { getSocketDetails, getTlsDetails } from './utils/helpers.js';
+import { IPReputationChecker } from '../../../security/classes.ipreputationchecker.js';
 
 /**
  * Interface for IP denylist entry