fix(mail): migrate filesystem helpers to fsUtils, update DKIM and mail APIs, harden SMTP client, and bump dependencies

ts/mail/core/classes.bouncemanager.ts

@@ -650,7 +650,7 @@ export class BounceManager {
         await this.storageManager.set('/email/bounces/suppression-list.json', suppressionData);
       } else {
         // Fall back to filesystem
-        plugins.smartfile.memory.toFsSync(
+        plugins.fsUtils.toFsSync(
           suppressionData,
           plugins.path.join(paths.dataDir, 'emails', 'suppression_list.json')
         );
@@ -744,9 +744,9 @@ export class BounceManager {
         
         // Ensure directory exists
         const bounceDir = plugins.path.join(paths.dataDir, 'emails', 'bounces');
-        plugins.smartfile.fs.ensureDirSync(bounceDir);
+        plugins.fsUtils.ensureDirSync(bounceDir);
         
-        plugins.smartfile.memory.toFsSync(bounceData, bouncePath);
+        plugins.fsUtils.toFsSync(bounceData, bouncePath);
       }
     } catch (error) {
       logger.log('error', `Failed to save bounce record: ${error.message}`);

ts/mail/core/classes.email.ts

@@ -613,17 +613,18 @@ export class Email {
     }
     
     // Add attachments
+    const smartFileFactory = plugins.smartfile.SmartFileFactory.nodeFs();
     for (const attachment of this.attachments) {
-      const smartAttachment = await plugins.smartfile.SmartFile.fromBuffer(
+      const smartAttachment = smartFileFactory.fromBuffer(
         attachment.filename,
         attachment.content
       );
-      
+
       // Set content type if available
       if (attachment.contentType) {
         (smartAttachment as any).contentType = attachment.contentType;
       }
-      
+
       smartmail.addAttachment(smartAttachment);
     }