feat: collect assignment and disposition events for statistics

config/services.yaml

@@ -105,6 +105,13 @@ services:
             $emailTextsFile: '%kernel.project_dir%/config/email_texts.yaml'
             $mailingBusTransport: '%mailing_bus_transport%'
 
+    # Tagged by interface rather than listed by hand: order between collectors is
+    # irrelevant, so the only thing an explicit list could add here is the chance to
+    # forget one, which would silently stop a metric being recorded.
+    _instanceof:
+        App\Service\Statistics\Collector\StatisticsCollectorInterface:
+            tags: ['app.statistics_collector']
+
     App\:
         resource: '../src/'
         exclude:
@@ -246,6 +253,10 @@ services:
             $datevEmailRecipient: '%env(DATEV_EMAIL_RECIPIENT)%'
             $datevEmailSender: '%env(DATEV_EMAIL_SENDER)%'
 
+    App\EventListener\StatisticsChangeSetListener:
+        arguments:
+            $collectors: !tagged_iterator app.statistics_collector
+
     App\RequiredTeamerCheck\RequiredTeamerCheckRegistry:
         arguments:
             # Presentation order only. Each check must point at a page that clears