feat(inbox): Enable conversation continuity for social channels (#11079)

## Summary
This PR enables and surfaces **conversation workflow** for social-style
channels that should support either:
- `Create new conversations` after resolve, or
- `Reopen same conversation`

## What is included
- Adds the conversation workflow setting UI as card-based options in
Inbox Settings.
- Expands channel availability in settings to include channels like:
  - Telegram
  - TikTok
  - Instagram
  - Line
  - WhatsApp
  - Facebook
- Updates conversation selection behavior for Line incoming messages to
respect the workflow (reopen vs create-new-after-resolved).
- Updates TikTok conversation selection behavior to respect the workflow
(reopen vs create-new-after-resolved).
- Keeps email behavior unchanged (always starts a new thread).

Fixes: https://github.com/chatwoot/chatwoot/issues/8426

## Screenshot

<img width="1400" height="900" alt="pr11079-workflow-sender-clear-tight"
src="https://github.com/user-attachments/assets/9456821f-8d83-4924-8dcf-7503c811a7b1"
/>


## How To Reproduce
1. Open `Settings -> Inboxes ->
<Telegram/TikTok/Instagram/Line/Facebook/WhatsApp inbox> -> Settings`.
2. Verify **Conversation workflow** is visible with the two card
options.
3. Toggle between both options and save.
4. For Line and TikTok, verify resolved-conversation behavior follows
the selected workflow.

## Testing
- `RAILS_ENV=test bundle exec rspec
spec/builders/messages/instagram/message_builder_spec.rb:213
spec/builders/messages/instagram/message_builder_spec.rb:255
spec/builders/messages/instagram/messenger/message_builder_spec.rb:228
spec/builders/messages/instagram/messenger/message_builder_spec.rb:293
spec/services/tiktok/message_service_spec.rb`
- Result: `16 examples, 0 failures`

## Follow-up
- Migrate Website Live Chat workflow settings into this same
conversation-workflow settings model.
- Add Voice channel support for this workflow setting.

---------

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>
Co-authored-by: iamsivin <iamsivin@gmail.com>

spec/services/telegram/incoming_message_service_spec.rb

@@ -410,6 +410,94 @@ describe Telegram::IncomingMessageService do
         expect(telegram_channel.inbox.messages.first.attachments.first.file_type).to eq('contact')
       end
     end
+
+    context 'when lock_to_single_conversation is false' do
+      before do
+        telegram_channel.inbox.update(lock_to_single_conversation: false)
+      end
+
+      it 'creates a new conversation when all previous conversations are resolved' do
+        # Create a contact and a resolved conversation
+        params = {
+          'update_id' => 2_342_342_343_242,
+          'message' => { 'text' => 'first message' }.merge(message_params)
+        }.with_indifferent_access
+
+        described_class.new(inbox: telegram_channel.inbox, params: params).perform
+
+        # Mark the conversation as resolved
+        conversation = telegram_channel.inbox.conversations.last
+        conversation.update(status: :resolved)
+
+        # Send a new message
+        new_params = {
+          'update_id' => 2_342_342_343_243,
+          'message' => { 'text' => 'second message' }.merge(message_params)
+        }.with_indifferent_access
+
+        described_class.new(inbox: telegram_channel.inbox, params: new_params).perform
+
+        # Should create a new conversation
+        expect(telegram_channel.inbox.conversations.count).to eq(2)
+        expect(telegram_channel.inbox.conversations.last.messages.first.content).to eq('second message')
+      end
+
+      it 'uses the existing conversation when there is an unresolved conversation' do
+        # Create a contact and an unresolved conversation
+        params = {
+          'update_id' => 2_342_342_343_242,
+          'message' => { 'text' => 'first message' }.merge(message_params)
+        }.with_indifferent_access
+
+        described_class.new(inbox: telegram_channel.inbox, params: params).perform
+
+        # Send a new message
+        new_params = {
+          'update_id' => 2_342_342_343_243,
+          'message' => { 'text' => 'second message' }.merge(message_params)
+        }.with_indifferent_access
+
+        described_class.new(inbox: telegram_channel.inbox, params: new_params).perform
+
+        # Should use the same conversation
+        expect(telegram_channel.inbox.conversations.count).to eq(1)
+        expect(telegram_channel.inbox.conversations.last.messages.count).to eq(2)
+        expect(telegram_channel.inbox.conversations.last.messages.last.content).to eq('second message')
+      end
+    end
+
+    context 'when lock_to_single_conversation is true' do
+      before do
+        telegram_channel.inbox.update(lock_to_single_conversation: true)
+      end
+
+      it 'uses the existing conversation even when it is resolved' do
+        # Create a contact and a resolved conversation
+        params = {
+          'update_id' => 2_342_342_343_242,
+          'message' => { 'text' => 'first message' }.merge(message_params)
+        }.with_indifferent_access
+
+        described_class.new(inbox: telegram_channel.inbox, params: params).perform
+
+        # Mark the conversation as resolved
+        conversation = telegram_channel.inbox.conversations.last
+        conversation.update(status: :resolved)
+
+        # Send a new message
+        new_params = {
+          'update_id' => 2_342_342_343_243,
+          'message' => { 'text' => 'second message' }.merge(message_params)
+        }.with_indifferent_access
+
+        described_class.new(inbox: telegram_channel.inbox, params: new_params).perform
+
+        # Should use the same conversation
+        expect(telegram_channel.inbox.conversations.count).to eq(1)
+        expect(telegram_channel.inbox.conversations.last.messages.count).to eq(2)
+        expect(telegram_channel.inbox.conversations.last.messages.last.content).to eq('second message')
+      end
+    end
   end
 
   context 'when lock to single conversation is enabled' do