feat: Add twilio content templates (#12277)

Implements comprehensive Twilio WhatsApp content template support (Phase
1) enabling text, media, and quick reply templates with proper parameter
conversion, sync capabilities, and feature flag protection.

###  Features Implemented

  **Template Types Supported**

  - Basic Text Templates: Simple text with variables ({{1}}, {{2}})
  - Media Templates: Image/Video/Document templates with text variables
  - Quick Reply Templates: Interactive button templates
- Phase 2 (Future): List Picker, Call-to-Action, Catalog, Carousel,
Authentication templates

  **Template Synchronization**

- API Endpoint: POST
/api/v1/accounts/{account_id}/inboxes/{inbox_id}/sync_templates
  - Background Job: Channels::Twilio::TemplatesSyncJob
  - Storage: JSONB format in channel_twilio_sms.content_templates
  - Auto-categorization: UTILITY, MARKETING, AUTHENTICATION categories

 ###  Template Examples Tested


  #### Text template
```
  { "name": "greet", "language": "en" }
```
  #### Template with variables
```
  { "name": "order_status", "parameters": [{"type": "body", "parameters": [{"text": "John"}]}] }
```

  #### Media template with image
```
  { "name": "product_showcase", "parameters": [
    {"type": "header", "parameters": [{"image": {"link": "image.jpg"}}]},
    {"type": "body", "parameters": [{"text": "iPhone"}, {"text": "$999"}]}
  ]}
```
#### Preview

<img width="1362" height="1058" alt="CleanShot 2025-08-26 at 10 01
51@2x"
src="https://github.com/user-attachments/assets/cb280cea-08c3-44ca-8025-58a96cb3a451"
/>

<img width="1308" height="1246" alt="CleanShot 2025-08-26 at 10 02
02@2x"
src="https://github.com/user-attachments/assets/9ea8537a-61e9-40f5-844f-eaad337e1ddd"
/>

#### User guide

https://www.chatwoot.com/hc/user-guide/articles/1756195741-twilio-content-templates

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>

app/javascript/dashboard/routes/dashboard/settings/inbox/settingsPage/ConfigurationPage.vue

@@ -125,6 +125,19 @@ export default {
     >
       <woot-code :script="inbox.callback_webhook_url" lang="html" />
     </SettingsSection>
+    <SettingsSection
+      v-if="isATwilioWhatsAppChannel"
+      :title="$t('INBOX_MGMT.SETTINGS_POPUP.WHATSAPP_TEMPLATES_SYNC_TITLE')"
+      :sub-title="
+        $t('INBOX_MGMT.SETTINGS_POPUP.WHATSAPP_TEMPLATES_SYNC_SUBHEADER')
+      "
+    >
+      <div class="flex justify-start items-center mt-2">
+        <NextButton :disabled="isSyncingTemplates" @click="syncTemplates">
+          {{ $t('INBOX_MGMT.SETTINGS_POPUP.WHATSAPP_TEMPLATES_SYNC_BUTTON') }}
+        </NextButton>
+      </div>
+    </SettingsSection>
   </div>
   <div v-else-if="isAVoiceChannel" class="mx-8">
     <SettingsSection