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>

app/javascript/dashboard/i18n/locale/en/inboxMgmt.json

@@ -592,8 +592,10 @@
         "DISABLED": "Disabled"
       },
       "LOCK_TO_SINGLE_CONVERSATION": {
-        "ENABLED": "Enabled",
-        "DISABLED": "Disabled"
+        "ENABLED": "Reopen same conversation",
+        "DISABLED": "Create new conversations",
+        "ENABLED_DESCRIPTION": "When a contact messages again, the previous conversation will be reopened.",
+        "DISABLED_DESCRIPTION": "A new conversation will be created each time after the previous one is resolved."
       },
       "ENABLE_HMAC": {
         "LABEL": "Enable"
@@ -713,8 +715,8 @@
       "SENDER_NAME_SECTION_TEXT": "Enable/Disable showing Agent's name in email, if disabled it will show business name",
       "ENABLE_CONTINUITY_VIA_EMAIL": "Enable conversation continuity via email",
       "ENABLE_CONTINUITY_VIA_EMAIL_SUB_TEXT": "Conversations will continue over email if the contact email address is available.",
-      "LOCK_TO_SINGLE_CONVERSATION": "Lock to single conversation",
-      "LOCK_TO_SINGLE_CONVERSATION_SUB_TEXT": "Enable or disable multiple conversations for the same contact in this inbox",
+      "LOCK_TO_SINGLE_CONVERSATION": "Conversation Routing",
+      "LOCK_TO_SINGLE_CONVERSATION_SUB_TEXT": "Configure conversation creation for existing contacts",
       "INBOX_UPDATE_TITLE": "Inbox Settings",
       "INBOX_UPDATE_SUB_TEXT": "Update your inbox settings",
       "AUTO_ASSIGNMENT_SUB_TEXT": "Enable or disable the automatic assignment of new conversations to the agents added to this inbox.",