chore: Migrate mailers from the worker to jobs (#12331)

Previously, email replies were handled inside workers. There was no
execution logs. This meant if emails silently failed (as reported by a
customer), we had no way to trace where the issue happened, the only
assumption was “no error = mail sent.”

By moving email handling into jobs, we now have proper execution logs
for each attempt. This makes it easier to debug delivery issues and
would have better visibility when investigating customer reports.

Fixes
https://linear.app/chatwoot/issue/CW-5538/emails-are-not-sentdelivered-to-the-contact

---------

Co-authored-by: Sojan Jose <sojan@pepalo.com>
Co-authored-by: Shivam Mishra <scm.mymail@gmail.com>

spec/models/message_spec.rb

@@ -316,43 +316,69 @@ RSpec.describe Message do
     end
 
     context 'with conversation continuity' do
-      it 'calls notify email method on after save for outgoing messages in website channel' do
-        allow(ConversationReplyEmailWorker).to receive(:perform_in).and_return(true)
-        message.message_type = 'outgoing'
-        message.save!
-        expect(ConversationReplyEmailWorker).to have_received(:perform_in)
+      let(:inbox_with_continuity) do
+        create(:inbox, account: message.account,
+                       channel: build(:channel_widget, account: message.account, continuity_via_email: true))
       end
 
-      it 'does not call notify email for website channel if continuity is disabled' do
-        message.inbox = create(:inbox, account: message.account,
-                                       channel: build(:channel_widget, account: message.account, continuity_via_email: false))
-        allow(ConversationReplyEmailWorker).to receive(:perform_in).and_return(true)
+      it 'schedules email notification for outgoing messages in website channel' do
+        message.inbox = inbox_with_continuity
+        message.conversation.update!(inbox: inbox_with_continuity)
+        message.conversation.contact.update!(email: 'test@example.com')
         message.message_type = 'outgoing'
-        message.save!
-        expect(ConversationReplyEmailWorker).not_to have_received(:perform_in)
+
+        # Perform jobs inline to test full integration
+        perform_enqueued_jobs do
+          message.save!
+        end
+
+        # Verify the email worker is eventually scheduled through the service
+        jobs_for_conversation_count = ConversationReplyEmailWorker.jobs.count { |job| job['args'].first == message.conversation.id }
+        expect(jobs_for_conversation_count).to eq(1)
       end
 
-      it 'wont call notify email method for private notes' do
+      it 'does not schedule email for website channel if continuity is disabled' do
+        inbox_without_continuity = create(:inbox, account: message.account,
+                                                  channel: build(:channel_widget, account: message.account, continuity_via_email: false))
+        message.inbox = inbox_without_continuity
+        message.conversation.update!(inbox: inbox_without_continuity)
+        message.conversation.contact.update!(email: 'test@example.com')
+        message.message_type = 'outgoing'
+
+        initial_job_count = ConversationReplyEmailWorker.jobs.count { |job| job['args'].first == message.conversation.id }
+
+        perform_enqueued_jobs do
+          message.save!
+        end
+
+        # No new jobs should be scheduled for this conversation
+        jobs_for_conversation_count = ConversationReplyEmailWorker.jobs.count { |job| job['args'].first == message.conversation.id }
+        expect(jobs_for_conversation_count).to eq(initial_job_count)
+      end
+
+      it 'does not schedule email for private notes' do
+        message.inbox = inbox_with_continuity
+        message.conversation.update!(inbox: inbox_with_continuity)
+        message.conversation.contact.update!(email: 'test@example.com')
         message.private = true
-        allow(ConversationReplyEmailWorker).to receive(:perform_in).and_return(true)
-        message.save!
-        expect(ConversationReplyEmailWorker).not_to have_received(:perform_in)
-      end
-
-      it 'calls EmailReply worker if the channel is email' do
-        message.inbox = create(:inbox, account: message.account, channel: build(:channel_email, account: message.account))
-        allow(EmailReplyWorker).to receive(:perform_in).and_return(true)
         message.message_type = 'outgoing'
-        message.content_attributes = { email: { text_content: { quoted: 'quoted text' } } }
-        message.save!
-        expect(EmailReplyWorker).to have_received(:perform_in).with(1.second, message.id)
+
+        initial_job_count = ConversationReplyEmailWorker.jobs.count { |job| job['args'].first == message.conversation.id }
+
+        perform_enqueued_jobs do
+          message.save!
+        end
+
+        # No new jobs should be scheduled for this conversation
+        jobs_for_conversation_count = ConversationReplyEmailWorker.jobs.count { |job| job['args'].first == message.conversation.id }
+        expect(jobs_for_conversation_count).to eq(initial_job_count)
       end
 
-      it 'wont call notify email method unless its website or email channel' do
-        message.inbox = create(:inbox, account: message.account, channel: build(:channel_api, account: message.account))
-        allow(ConversationReplyEmailWorker).to receive(:perform_in).and_return(true)
+      it 'calls SendReplyJob for all channels' do
+        allow(SendReplyJob).to receive(:perform_later).and_return(true)
+        message.message_type = 'outgoing'
         message.save!
-        expect(ConversationReplyEmailWorker).not_to have_received(:perform_in)
+        expect(SendReplyJob).to have_received(:perform_later).with(message.id)
       end
     end
   end