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/utils/adaptive-logging.ts

@@ -4,11 +4,11 @@
  * to maintain performance during high-concurrency scenarios
  */
 
-import * as plugins from '../../../../plugins.ts';
-import { logger } from '../../../../logger.ts';
-import { SecurityLogLevel, SecurityEventType } from '../constants.ts';
-import type { ISmtpSession } from '../interfaces.ts';
-import type { LogLevel, ISmtpLogOptions } from './logging.ts';
+import * as plugins from '../../../../plugins.js';
+import { logger } from '../../../../logger.js';
+import { SecurityLogLevel, SecurityEventType } from '../constants.js';
+import type { ISmtpSession } from '../interfaces.js';
+import type { LogLevel, ISmtpLogOptions } from './logging.js';
 
 /**
  * Log modes based on server load