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/routing/classes.dnsmanager.ts

@@ -1,6 +1,6 @@
-import * as plugins from '../../plugins.ts';
-import * as paths from '../../paths.ts';
-import { DKIMCreator } from '../security/classes.dkimcreator.ts';
+import * as plugins from '../../plugins.js';
+import * as paths from '../../paths.js';
+import { DKIMCreator } from '../security/classes.dkimcreator.js';
 
 /**
  * Interface for DNS record information
@@ -57,7 +57,7 @@ export class DNSManager {
     }
     
     // Ensure the DNS records directory exists
-    plugins.smartfile.fs.ensureDirSync(paths.dnsRecordsDir);
+    plugins.fs.mkdirSync(paths.dnsRecordsDir, { recursive: true });
   }
 
   /**
@@ -417,7 +417,7 @@ export class DNSManager {
   public async saveDnsRecommendations(domain: string, records: IDnsRecord[]): Promise<void> {
     try {
       const filePath = plugins.path.join(paths.dnsRecordsDir, `${domain}.recommendations.json`);
-      plugins.smartfile.memory.toFsSync(JSON.stringify(records, null, 2), filePath);
+      await plugins.smartfs.file(filePath).write(JSON.stringify(records, null, 2));
       console.log(`DNS recommendations for ${domain} saved to ${filePath}`);
     } catch (error) {
       console.error(`Error saving DNS recommendations for ${domain}:`, error);