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/classes.smtp.client.legacy.ts

@@ -1,10 +1,10 @@
-import * as plugins from '../../plugins.ts';
-import { logger } from '../../logger.ts';
+import * as plugins from '../../plugins.js';
+import { logger } from '../../logger.js';
 import { 
   SecurityLogger, 
   SecurityLogLevel, 
   SecurityEventType 
-} from '../../security/index.ts';
+} from '../../security/index.js';
 
 import { 
   MtaConnectionError, 
@@ -13,10 +13,10 @@ import {
   MtaConfigurationError,
   MtaTimeoutError,
   MtaProtocolError
-} from '../../errors/index.ts';
+} from '../../errors/index.js';
 
-import { Email } from '../core/classes.email.ts';
-import type { EmailProcessingMode } from './interfaces.ts';
+import { Email } from '../core/classes.email.js';
+import type { EmailProcessingMode } from './interfaces.js';
 
 // Custom error type extension
 interface NodeNetworkError extends Error {
@@ -851,22 +851,33 @@ export class SmtpClient {
       
       // Sign email
       const signOptions = {
-        domainName: this.options.dkim.domain,
-        keySelector: this.options.dkim.selector,
+        signingDomain: this.options.dkim.domain,
+        selector: this.options.dkim.selector,
         privateKey: this.options.dkim.privateKey,
-        headerFieldNames: this.options.dkim.headers || [
-          'from', 'to', 'subject', 'date', 'message-id'
+        canonicalization: 'relaxed/relaxed' as const,
+        algorithm: 'rsa-sha256' as const,
+        signTime: new Date(),
+        signatureData: [
+          {
+            signingDomain: this.options.dkim.domain,
+            selector: this.options.dkim.selector,
+            privateKey: this.options.dkim.privateKey,
+            algorithm: 'rsa-sha256',
+            canonicalization: 'relaxed/relaxed',
+          }
         ]
       };
-      
-      const signedEmail = await dkimSign(emailContent, signOptions);
-      
-      // Replace headers in original email
-      const dkimHeader = signedEmail.substring(0, signedEmail.indexOf('\r\n\r\n')).split('\r\n')
-        .find(line => line.startsWith('DKIM-Signature: '));
-      
-      if (dkimHeader) {
-        email.addHeader('DKIM-Signature', dkimHeader.substring('DKIM-Signature: '.length));
+
+      const signResult = await dkimSign(emailContent, signOptions);
+
+      // Add DKIM-Signature header from the signing result
+      if (signResult.signatures) {
+        const dkimHeader = signResult.signatures.split('\r\n')
+          .find(line => line.startsWith('DKIM-Signature: '));
+
+        if (dkimHeader) {
+          email.addHeader('DKIM-Signature', dkimHeader.substring('DKIM-Signature: '.length));
+        }
       }
       
       logger.log('debug', 'DKIM signature applied successfully');