feat: Add APIs for limit check in accounts (#7242)

app/helpers/billing_helper.rb

@@ -0,0 +1,21 @@
+module BillingHelper
+  private
+
+  def default_plan?(account)
+    installation_config = InstallationConfig.find_by(name: 'CHATWOOT_CLOUD_PLANS')
+    default_plan = installation_config&.value&.first
+
+    # Return false if not plans are configured, so that no checks are enforced
+    return false if default_plan.blank?
+
+    account.custom_attributes['plan_name'].nil? || account.custom_attributes['plan_name'] == default_plan['name']
+  end
+
+  def conversations_this_month(account)
+    account.conversations.where('created_at > ?', 30.days.ago).count
+  end
+
+  def non_web_inboxes(account)
+    account.inboxes.where.not(channel_type: Channel::WebWidget.to_s).count
+  end
+end