Generalize notifier copy: %{number} → %{name}, drop "Number" prefix

Substrate post-Phase-1 (#45) is generic single-resource CRUD, not
queue-only — `ItemTag.name` can be a queue number ("A001"), a pet
name ("Mittens"), a task title, etc. The copy "Number %{number} is
up" only reads correctly for the queue case, and the agent's renamer
doesn't substitute the word "Number" (it's not in the rename plan),
so the wrong copy ships to every renamed app.

Change to "%{name} is ready" — generalizes cleanly across the queue,
reservation, vet-clinic, and task-tracker domains the substrate
targets. Body unchanged.

Test passes; rubocop clean.

Author: dadachi

app/notifiers/item_tag_called_notifier.rb

@@ -12,7 +12,7 @@ class ItemTagCalledNotifier < ApplicationNotifier
 
   notification_methods do
     def title
-      I18n.t("notifiers.item_tag_called.title", number: record.name)
+      I18n.t("notifiers.item_tag_called.title", name: record.name)
     end
 
     def body

config/locales/en.yml

@@ -42,7 +42,7 @@ en:
 
   notifiers:
     item_tag_called:
-      title: "Number %{number} is up"
+      title: "%{name} is ready"
       body: "Please proceed to %{shop}."
 
   api:

test/notifiers/item_tag_called_notifier_test.rb

@@ -27,7 +27,7 @@ class ItemTagCalledNotifierTest < ActiveSupport::TestCase
     ItemTagCalledNotifier.with(record: @item_tag).deliver(@shopkeeper)
     notification = @shopkeeper.notifications.last
 
-    assert_equal I18n.t("notifiers.item_tag_called.title", number: @item_tag.name), notification.title
+    assert_equal I18n.t("notifiers.item_tag_called.title", name: @item_tag.name), notification.title
     assert_equal I18n.t("notifiers.item_tag_called.body", shop: @shop.name), notification.body
   end
 end