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/core/classes.bouncemanager.ts

@@ -1,9 +1,9 @@
-import * as plugins from '../../plugins.ts';
-import * as paths from '../../paths.ts';
-import { logger } from '../../logger.ts';
-import { SecurityLogger, SecurityLogLevel, SecurityEventType } from '../../security/index.ts';
+import * as plugins from '../../plugins.js';
+import * as paths from '../../paths.js';
+import { logger } from '../../logger.js';
+import { SecurityLogger, SecurityLogLevel, SecurityEventType } from '../../security/index.js';
 import { LRUCache } from 'lru-cache';
-import type { Email } from './classes.email.ts';
+import type { Email } from './classes.email.js';
 
 /**
  * Bounce types for categorizing the reasons for bounces
@@ -650,10 +650,9 @@ export class BounceManager {
         await this.storageManager.set('/email/bounces/suppression-list.json', suppressionData);
       } else {
         // Fall back to filesystem
-        plugins.smartfile.memory.toFsSync(
-          suppressionData,
+        await plugins.smartfs.file(
           plugins.path.join(paths.dataDir, 'emails', 'suppression_list.json')
-        );
+        ).write(suppressionData);
       }
     } catch (error) {
       logger.log('error', `Failed to save suppression list: ${error.message}`);
@@ -744,9 +743,9 @@ export class BounceManager {
         
         // Ensure directory exists
         const bounceDir = plugins.path.join(paths.dataDir, 'emails', 'bounces');
-        plugins.smartfile.fs.ensureDirSync(bounceDir);
-        
-        plugins.smartfile.memory.toFsSync(bounceData, bouncePath);
+        await plugins.smartfs.directory(bounceDir).recursive().create();
+
+        await plugins.smartfs.file(bouncePath).write(bounceData);
       }
     } catch (error) {
       logger.log('error', `Failed to save bounce record: ${error.message}`);