Fix error handling and improve naming consistency

- Use native error chaining in workflow (Error constructor with cause option)
- Fix job scheduling to use 'task' instead of 'workflow' property
- Rename processEmailsJob.ts to processEmailsTask.ts for consistency
- Update all imports and references while maintaining backward compatibility
- Add processEmailsTask export with processEmailsJob alias
- Bump version to 0.3.1

src/jobs/processEmailsTask.ts

@@ -0,0 +1,95 @@
+import type { PayloadRequest, Payload } from 'payload'
+import type { MailingService } from '../services/MailingService.js'
+
+/**
+ * Data passed to the process emails task
+ */
+export interface ProcessEmailsTaskData {
+  // Currently no data needed - always processes both pending and failed emails
+}
+
+/**
+ * Handler function for processing emails
+ * Used internally by the task definition
+ */
+export const processEmailsTaskHandler = async (
+  job: { data: ProcessEmailsTaskData },
+  context: { req: PayloadRequest; mailingService: MailingService }
+) => {
+  const { mailingService } = context
+
+  try {
+    console.log('🔄 Processing email queue (pending + failed emails)...')
+
+    // Process pending emails first
+    await mailingService.processEmails()
+
+    // Then retry failed emails
+    await mailingService.retryFailedEmails()
+
+    console.log('✅ Email queue processing completed successfully')
+  } catch (error) {
+    console.error('❌ Email queue processing failed:', error)
+    throw error
+  }
+}
+
+/**
+ * Task definition for processing emails
+ * This is what gets registered with Payload's job system
+ */
+export const processEmailsTask = {
+  slug: 'process-emails',
+  handler: async ({ job, req }: { job: any; req: any }) => {
+    // Get mailing context from payload
+    const payload = (req as any).payload
+    const mailingContext = payload.mailing
+
+    if (!mailingContext) {
+      throw new Error('Mailing plugin not properly initialized')
+    }
+
+    // Use the existing mailing service from context
+    await processEmailsTaskHandler(
+      job as { data: ProcessEmailsTaskData },
+      { req, mailingService: mailingContext.service }
+    )
+
+    return {
+      output: {
+        success: true,
+        message: 'Email queue processing completed successfully'
+      }
+    }
+  },
+  interfaceName: 'ProcessEmailsTask',
+}
+
+// For backward compatibility, export as processEmailsJob
+export const processEmailsJob = processEmailsTask
+
+/**
+ * Helper function to schedule an email processing job
+ * Used by the plugin during initialization and can be used by developers
+ */
+export const scheduleEmailsJob = async (
+  payload: Payload,
+  queueName: string,
+  delay?: number
+) => {
+  if (!payload.jobs) {
+    console.warn('PayloadCMS jobs not configured - emails will not be processed automatically')
+    return
+  }
+
+  try {
+    await payload.jobs.queue({
+      queue: queueName,
+      task: 'process-emails',
+      input: {},
+      waitUntil: delay ? new Date(Date.now() + delay) : undefined,
+    } as any)
+  } catch (error) {
+    console.error('Failed to schedule email processing job:', error)
+  }
+}