fix: remove unused working hours endpoint (#13839)

Fixes #13752

Removes the standalone `working_hours` API endpoint instead of fixing
only the callback typo in `WorkingHoursController`.

## Why

The route is not used by the dashboard. The supported product flow
already updates business hours through `PATCH
/api/v1/accounts/:account_id/inboxes/:id`.

The standalone endpoint was already unusable in practice:
- The controller callback pointed to the wrong method.
- Fixing that callback alone would still leave the endpoint blocked by
missing `WorkingHourPolicy` authorization.
- Keeping the route would preserve unsupported API surface without
making the product flow better.

## What this change does

- Removes `PATCH/PUT /api/v1/accounts/:account_id/working_hours/:id`.
- Deletes `Api::V1::Accounts::WorkingHoursController`.
- Leaves the inbox working-hours update path unchanged.

Compatibility note: this removes an undocumented endpoint that was
already unusable in practice. Working-hours updates should continue to
go through the supported inbox update API.

## Validation

- Ran `bin/rails routes -g working_hours` and confirmed the standalone
working-hours API route is no longer present.
- Searched for remaining `WorkingHoursController` and `resources
:working_hours` references.

---------

Co-authored-by: easonysliu <easonysliu@tencent.com>
Co-authored-by: Sojan Jose <sojan@pepalo.com>

app/controllers/api/v1/accounts/working_hours_controller.rb

@@ -1,18 +0,0 @@
-class Api::V1::Accounts::WorkingHoursController < Api::V1::Accounts::BaseController
-  before_action :check_authorization
-  before_action :fetch_webhook, only: [:update]
-
-  def update
-    @working_hour.update!(working_hour_params)
-  end
-
-  private
-
-  def working_hour_params
-    params.require(:working_hour).permit(:inbox_id, :open_hour, :open_minutes, :close_hour, :close_minutes, :closed_all_day)
-  end
-
-  def fetch_working_hour
-    @working_hour = Current.account.working_hours.find(params[:id])
-  end
-end

config/routes.rb

@@ -378,8 +378,6 @@ Rails.application.routes.draw do
               end
             end
           end
-          resources :working_hours, only: [:update]
-
           resources :portals do
             member do
               patch :archive