feat(treatment): select treatment behaviour by practice domain, not by if-branch

Everything that differs between specialties as data is already stored as data.
What is left is behaviour — when a case opens, what happens once a session ends —
so it becomes a TreatmentWorkflow resolved through a tagged-service registry.
The booking path calls one collaborator and never names a specialty; adding
dentistry is a new class, not an edit to confirmation.

A clinic that has chosen no practice domain still gets working multi-session
courses: DefaultTreatmentWorkflow answers for null and for any code without a
dedicated implementation, keeping "unset means behave as today, not error".
LaserTreatmentWorkflow is deliberately empty beyond claiming `beauty` — it is the
seam where laser-specific behaviour will land without disturbing anyone else.

Session due dates are anchored to the previous session's actual finish, so a
patient who comes twenty days late shifts the rest of their course instead of
getting the next session while it can still do nothing. Only the next session is
recomputed; later ones keep their estimate because they are anchored to nothing
yet.

Attachment targets the first session without an appointment rather than the
first open one: a patient booking again mid-course was otherwise matched to the
session that already had a booking, and the second appointment went nowhere.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/Appointment/Service/AppointmentConfirmationService.php

@@ -30,6 +30,7 @@ class AppointmentConfirmationService
         private readonly PaymentRepository     $paymentRepo,
         private readonly CommissionService     $commissionService,
         private readonly DomainContextResolver $domainResolver,
+        private readonly \App\Treatment\Service\TreatmentCaseStarter $treatmentCases,
         private readonly EntityManagerInterface $em,
         private readonly LoggerInterface       $logger,
     ) {}
@@ -72,7 +73,15 @@ class AppointmentConfirmationService
         $this->splitPaymentShares($appointment);
 
         try {
-            return $this->patientService->autoCreateOnAppointmentConfirm($appointment);
+            $session = $this->patientService->autoCreateOnAppointmentConfirm($appointment);
+
+            // هسته نمی‌داند دورهٔ درمان چیست: اگر سرویسِ نوبت پروتکل داشته باشد،
+            // workflowِ حوزهٔ فعالیت تصمیم می‌گیرد چه اتفاقی بیفتد.
+            if ($session !== null) {
+                $this->treatmentCases->onAppointmentConfirmed($appointment, $session);
+            }
+
+            return $session;
         } catch (\Throwable $e) {
             $this->logger->error('Auto-creating the patient record on confirm failed', [
                 'appointment_uuid' => $appointment->getUuid(),