controller v0.264.0: the household is told when an update is undone or held, in its language

app_update_undone / app_update_held events (09 decision 15), on by
default and seeded once on existing boxes; R-606 update sentences as
key+args rendered per reader; R-646 startup applied-meta backfill for
apps current with the catalog; R-620 a disabled notifier WARNs once per
event type. Needs hub v0.120.0.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

controller/internal/web/templates/settings_notifications.html

@@ -74,6 +74,14 @@
                         <input type="checkbox" name="event_app_start_failed" {{with .NotificationPrefs}}{{range .EnabledEvents}}{{if eq . "app_start_failed"}}checked{{end}}{{end}}{{end}}>
                         <span class="toggle-label">{{T "settings_notifications.alkalmazas_nem_fut"}}</span>
                     </label>
+                    <label class="toggle">
+                        <input type="checkbox" name="event_app_update_undone" {{with .NotificationPrefs}}{{range .EnabledEvents}}{{if eq . "app_update_undone"}}checked{{end}}{{end}}{{end}}>
+                        <span class="toggle-label">{{T "settings_notifications.app_update_undone"}}</span>
+                    </label>
+                    <label class="toggle">
+                        <input type="checkbox" name="event_app_update_held" {{with .NotificationPrefs}}{{range .EnabledEvents}}{{if eq . "app_update_held"}}checked{{end}}{{end}}{{end}}>
+                        <span class="toggle-label">{{T "settings_notifications.app_update_held"}}</span>
+                    </label>
                 </div>
             </div>
             <div class="form-group">