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.emailsignjob.ts

@@ -1,5 +1,5 @@
-import * as plugins from '../../plugins.ts';
-import type { UnifiedEmailServer } from '../routing/classes.unified.email.server.ts';
+import * as plugins from '../../plugins.js';
+import type { UnifiedEmailServer } from '../routing/classes.unified.email.server.js';
 
 interface Headers {
   [key: string]: string;
@@ -27,37 +27,21 @@ export class EmailSignJob {
   }
 
   public async getSignatureHeader(emailMessage: string): Promise<string> {
+    const privateKey = await this.loadPrivateKey();
     const signResult = await plugins.dkimSign(emailMessage, {
-      // Optional, default canonicalization, default is "relaxed/relaxed"
-      canonicalization: 'relaxed/relaxed', // c=
-
-      // Optional, default signing and hashing algorithm
-      // Mostly useful when you want to use rsa-sha1, otherwise no need to set
+      signingDomain: this.jobOptions.domain,
+      selector: this.jobOptions.selector,
+      privateKey,
+      canonicalization: 'relaxed/relaxed',
       algorithm: 'rsa-sha256',
-
-      // Optional, default is current time
-      signTime: new Date(), // t=
-
-      // Keys for one or more signatures
-      // Different signatures can use different algorithms (mostly useful when
-      // you want to sign a message both with RSA and Ed25519)
+      signTime: new Date(),
       signatureData: [
         {
-          signingDomain: this.jobOptions.domain, // d=
-          selector: this.jobOptions.selector, // s=
-          // supported key types: RSA, Ed25519
-          privateKey: await this.loadPrivateKey(), // k=
-
-          // Optional algorithm, default is derived from the key.
-          // Overrides whatever was set in parent object
+          signingDomain: this.jobOptions.domain,
+          selector: this.jobOptions.selector,
+          privateKey,
           algorithm: 'rsa-sha256',
-
-          // Optional signature specifc canonicalization, overrides whatever was set in parent object
-          canonicalization: 'relaxed/relaxed', // c=
-
-          // Maximum number of canonicalized body bytes to sign (eg. the "l=" tag).
-          // Do not use though. This is available only for compatibility testing.
-          // maxBodyLength: 12345
+          canonicalization: 'relaxed/relaxed',
         },
       ],
     });