feat: Add WhatsApp health monitoring and self-service registration completion (#12556)

Fixes
https://linear.app/chatwoot/issue/CW-5692/whatsapp-es-numbers-stuck-in-pending-due-to-premature-registration


###  Problem  
Multiple customers reported that their WhatsApp numbers remain stuck in
**Pending** in WhatsApp Manager even after successful onboarding.

- Our system triggers a **registration call**
(`/<PHONE_NUMBER_ID>/register`) as soon as the number is OTP verified.
- In many cases, Meta hasn’t finished **display name
review/provisioning**, so the call fails with:

  ```
  code: 100, error_subcode: 2388001
  error_user_title: "Cannot Create Certificate"
error_user_msg: "Your display name could not be processed. Please edit
your display name and try again."
  ```

- This leaves the number stuck in Pending, no messaging can start until
we manually retry registration.
- Some customers have reported being stuck in this state for **7+
days**.

###  Root cause  
- We only check `code_verification_status = VERIFIED` before attempting
registration.
- We **don’t wait** for display name provisioning (`name_status` /
`platform_type`) to be complete.
- As a result, registration fails prematurely and the number never
transitions out of Pending.

### Solution  

#### 1. Health Status Monitoring  
- Build a backend service to fetch **real-time health data** from Graph
API:
  - `code_verification_status`  
  - `name_status` / `display_name_status`  
  - `platform_type`  
  - `throughput.level`  
  - `messaging_limit_tier`  
  - `quality_rating`  
- Expose health data via API
(`/api/v1/accounts/:account_id/inboxes/:id/health`).
- Display this in the UI as an **Account Health tab** with clear badges
and direct links to WhatsApp Manager.

#### 2. Smarter Registration Logic  
- Update `WebhookSetupService` to include a **dual-condition check**:  
  - Register if:  
    1. Phone is **not verified**, OR  
2. Phone is **verified but provisioning incomplete** (`platform_type =
NOT_APPLICABLE`, `throughput.level = NOT_APPLICABLE`).
- Skip registration if number is already provisioned.  
- Retry registration automatically when stuck.  
- Provide a UI banner with complete registration button so customers can
retry without manual support.

### Screenshot
<img width="2292" height="1344" alt="CleanShot 2025-09-30 at 16 01
03@2x"
src="https://github.com/user-attachments/assets/1c417d2a-b11c-475e-b092-3c5671ee59a7"
/>

---------

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

config/routes.rb

@@ -193,6 +193,7 @@ Rails.application.routes.draw do
             post :set_agent_bot, on: :member
             delete :avatar, on: :member
             post :sync_templates, on: :member
+            get :health, on: :member
           end
           resources :inbox_members, only: [:create, :show], param: :inbox_id do
             collection do