feat(payment): unify payment flow with new pure redirect entry and update related endpoints

src/Payment/Entity/Payment.php

@@ -110,6 +110,7 @@ class Payment
     public function setReferenceId(?string $r): self         { $this->referenceId = $r; $this->touch(); return $this; }
     public function setStatus(string $s): self               { $this->status = $s; $this->touch(); return $this; }
     public function setCallbackIp(?string $ip): self         { $this->callbackIp = $ip; $this->touch(); return $this; }
+    public function setFrontendAddress(?string $a): self     { $this->frontendAddress = $a ?: null; $this->touch(); return $this; }
 
     private function touch(): void { $this->updatedAt = time(); }