chore: improve plan-based feature handling with plan hierarchy (#11335)

- Refactor HandleStripeEventService to better manage features by plan
- Add constants for features available in each plan tier (Startup,
Business, Enterprise)
- Add channel_instagram to Startup plan features
- Improve downgrade handling to properly disable higher-tier features
- Clean up and optimize tests for maintainability
- Add comprehensive test coverage for plan upgrades and downgrades

---------

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/dashboards/account_dashboard.rb

@@ -9,10 +9,17 @@ class AccountDashboard < Administrate::BaseDashboard
   # on pages throughout the dashboard.
 
   enterprise_attribute_types = if ChatwootApp.enterprise?
-                                 {
-                                   limits: Enterprise::AccountLimitsField,
-                                   all_features: Enterprise::AccountFeaturesField
+                                 attributes = {
+                                   limits: AccountLimitsField
                                  }
+
+                                 # Only show manually managed features in Chatwoot Cloud deployment
+                                 attributes[:manually_managed_features] = ManuallyManagedFeaturesField if ChatwootApp.chatwoot_cloud?
+
+                                 # Add all_features last so it appears after manually_managed_features
+                                 attributes[:all_features] = AccountFeaturesField
+
+                                 attributes
                                else
                                  {}
                                end
@@ -46,7 +53,14 @@ class AccountDashboard < Administrate::BaseDashboard
 
   # SHOW_PAGE_ATTRIBUTES
   # an array of attributes that will be displayed on the model's show page.
-  enterprise_show_page_attributes = ChatwootApp.enterprise? ? %i[custom_attributes limits all_features] : []
+  enterprise_show_page_attributes = if ChatwootApp.enterprise?
+                                      attrs = %i[custom_attributes limits]
+                                      attrs << :manually_managed_features if ChatwootApp.chatwoot_cloud?
+                                      attrs << :all_features
+                                      attrs
+                                    else
+                                      []
+                                    end
   SHOW_PAGE_ATTRIBUTES = (%i[
     id
     name
@@ -61,7 +75,14 @@ class AccountDashboard < Administrate::BaseDashboard
   # FORM_ATTRIBUTES
   # an array of attributes that will be displayed
   # on the model's form (`new` and `edit`) pages.
-  enterprise_form_attributes = ChatwootApp.enterprise? ? %i[limits all_features] : []
+  enterprise_form_attributes = if ChatwootApp.enterprise?
+                                 attrs = %i[limits]
+                                 attrs << :manually_managed_features if ChatwootApp.chatwoot_cloud?
+                                 attrs << :all_features
+                                 attrs
+                               else
+                                 []
+                               end
   FORM_ATTRIBUTES = (%i[
     name
     locale
@@ -96,6 +117,11 @@ class AccountDashboard < Administrate::BaseDashboard
   # to prevent an error from being raised (wrong number of arguments)
   # Reference: https://github.com/thoughtbot/administrate/pull/2356/files#diff-4e220b661b88f9a19ac527c50d6f1577ef6ab7b0bed2bfdf048e22e6bfa74a05R204
   def permitted_attributes(action)
-    super + [limits: {}]
+    attrs = super + [limits: {}]
+
+    # Add manually_managed_features to permitted attributes only for Chatwoot Cloud
+    attrs << { manually_managed_features: [] } if ChatwootApp.chatwoot_cloud?
+
+    attrs
   end
 end