fix: Revoke Linear OAuth token when integration is deleted (#11838)

When users delete the Linear integration from their Chatwoot dashboard,
the access token remains valid in Linear's system. This causes the
integration to still appear as connected in Linear's UI, even though
it's been removed from Chatwoot. Users need to manually disconnect from
Linear's side to fully remove the integration.


https://www.loom.com/share/5c102cbdf02e49bcb7a6fa6d409b531a?sid=0c664250-c867-4fc8-b44d-e1c1165337a7

app/controllers/api/v1/accounts/integrations/linear_controller.rb

@@ -3,6 +3,7 @@ class Api::V1::Accounts::Integrations::LinearController < Api::V1::Accounts::Bas
   before_action :fetch_hook, only: [:destroy]
 
   def destroy
+    revoke_linear_token
     @hook.destroy!
     head :ok
   end
@@ -120,4 +121,15 @@ class Api::V1::Accounts::Integrations::LinearController < Api::V1::Accounts::Bas
   def fetch_hook
     @hook = Integrations::Hook.where(account: Current.account).find_by(app_id: 'linear')
   end
+
+  def revoke_linear_token
+    return unless @hook&.access_token
+
+    begin
+      linear_client = Linear.new(@hook.access_token)
+      linear_client.revoke_token
+    rescue StandardError => e
+      Rails.logger.error "Failed to revoke Linear token: #{e.message}"
+    end
+  end
 end