feat(csat): Add WhatsApp utility template analyzer with rewrite guidance (#13575)

CSAT templates for WhatsApp are submitted as Utility, but Meta may
reclassify them as Marketing based on content, which can significantly
increase messaging costs.
This PR introduces a Captain-powered CSAT template analyzer for
WhatsApp/Twilio WhatsApp that predicts utility fit, explains likely
risks, and suggests safer rewrites before submission. The flow is manual
(button-triggered), Captain-gated, and applies rewrites only on explicit
user action. It also updates UX copy to clearly set expectations: the
system submits as Utility, Meta makes the final categorization decision.

Fixes
https://linear.app/chatwoot/issue/CW-6424/ai-powered-whatsapp-template-classifier-for-csat-submissions


https://github.com/user-attachments/assets/8fd1d6db-2f91-447c-9771-3de271b16fd9

app/services/whatsapp/csat_template_service.rb

@@ -2,7 +2,7 @@ class Whatsapp::CsatTemplateService
   DEFAULT_BUTTON_TEXT = 'Please rate us'.freeze
   DEFAULT_LANGUAGE = 'en'.freeze
   WHATSAPP_API_VERSION = 'v14.0'.freeze
-  TEMPLATE_CATEGORY = 'MARKETING'.freeze
+  TEMPLATE_CATEGORY = 'UTILITY'.freeze
   TEMPLATE_STATUS_PENDING = 'PENDING'.freeze
 
   def initialize(whatsapp_channel)