BREAKING CHANGE: Remove sendEmailWorkflow, add immediate processing to sendEmailTask

- Remove entire workflows directory and sendEmailWorkflow
- Factor out email processing logic into reusable utilities (emailProcessor.ts)
- Add processImmediately option to sendEmailTask input schema
- Update sendEmailTask to process emails immediately when requested
- Update processEmailsTask to use shared processing utilities
- Remove workflow-related exports and plugin configuration
- Simplify documentation to focus on unified task approach
- Export new email processing utilities (processEmailById, processAllEmails)
- Bump version to 0.4.0 (breaking change - workflows removed)

Migration: Use sendEmailTask with processImmediately: true instead of sendEmailWorkflow

src/utils/emailProcessor.ts

@@ -0,0 +1,39 @@
+import type { Payload } from 'payload'
+
+/**
+ * Processes a single email by ID using the mailing service
+ * @param payload Payload instance
+ * @param emailId The ID of the email to process
+ * @returns Promise that resolves when email is processed
+ */
+export async function processEmailById(payload: Payload, emailId: string): Promise<void> {
+  // Get mailing context from payload
+  const mailingContext = (payload as any).mailing
+
+  if (!mailingContext || !mailingContext.service) {
+    throw new Error('Mailing plugin not properly initialized')
+  }
+
+  // Process the specific email
+  await mailingContext.service.processEmailItem(emailId)
+}
+
+/**
+ * Processes all pending and failed emails using the mailing service
+ * @param payload Payload instance
+ * @returns Promise that resolves when all emails are processed
+ */
+export async function processAllEmails(payload: Payload): Promise<void> {
+  // Get mailing context from payload
+  const mailingContext = (payload as any).mailing
+
+  if (!mailingContext || !mailingContext.service) {
+    throw new Error('Mailing plugin not properly initialized')
+  }
+
+  // Process pending emails first
+  await mailingContext.service.processEmails()
+
+  // Then retry failed emails
+  await mailingContext.service.retryFailedEmails()
+}