Fix account destroy cascade gaps

Account incineration could leave orphaned records due to missing cascade
declarations and async jobs failing when the account was already gone.

Cascade fixes:
- Add Account::Searchable concern to clean up Search::Query (delete_all)
  and Search::Record (destroy_all, respects SQLite FTS dependent: :destroy)
- Add before_destroy in Account::Storage to delete storage entries
- Suppress storage entry recording during incineration so attachment
  purge callbacks don't create entries or enqueue materialize jobs
- Guard Access#clean_inaccessible_data_later with unless user.destroyed?
  to avoid enqueuing pointless jobs during user cascade

Job tenancy:
- Extract AccountTenanted concern from the global ActiveJob initializer
  into ApplicationJob (include) with targeted prepends for
  ActionMailer::MailDeliveryJob and Turbo broadcast jobs
- Defer account resolution from deserialize to perform so that missing
  accounts raise DeserializationError inside the execution path where
  discard_on can handle it

Tests:
- Comprehensive incineration test covering 35 model types with
  before/after assertions and full enqueued job processing
- Mailer deliver_later test verifying account context survives job
  serialization for multi-account users
- Turbo broadcast test verifying account-scoped URLs in rendered partials

config/initializers/active_job.rb

@@ -1,39 +1,15 @@
 # frozen_string_literal: true
 
-# inspired from code in ActiveRecord::Tenanted
-module FizzyActiveJobExtensions
-  extend ActiveSupport::Concern
-
-  prepended do
-    attr_reader :account
-    self.enqueue_after_transaction_commit = true
-  end
-
-  def initialize(...)
-    super
-    @account = Current.account
-  end
-
-  def serialize
-    super.merge({ "account" => @account&.to_gid })
-  end
-
-  def deserialize(job_data)
-    super
-    if _account = job_data.fetch("account", nil)
-      @account = GlobalID::Locator.locate(_account)
-    end
-  end
-
-  def perform_now
-    if account.present?
-      Current.with_account(account) { super }
-    else
-      super
-    end
-  end
-end
-
 ActiveSupport.on_load(:active_job) do
-  prepend FizzyActiveJobExtensions
+  self.enqueue_after_transaction_commit = true
+end
+
+ActiveSupport.on_load(:action_mailer) do
+  ActionMailer::MailDeliveryJob.prepend AccountTenanted
+end
+
+Rails.application.config.after_initialize do
+  Turbo::Streams::ActionBroadcastJob.prepend AccountTenanted
+  Turbo::Streams::BroadcastJob.prepend AccountTenanted
+  Turbo::Streams::BroadcastStreamJob.prepend AccountTenanted
 end