Update project 3 iteration feat: core booking pipeline, webhook and async pdf worker CORE COPLETE

backend/schemas/payment.py

@@ -0,0 +1,14 @@
+from pydantic import BaseModel, field_validator
+
+
+class PaymentWebhookRequest(BaseModel):
+    ticket_id: int
+    idempotency_key: str
+    status: str
+
+    @field_validator("status")
+    @classmethod
+    def status_must_be_success(cls, v: str) -> str:
+        if v != "success":
+            raise ValueError("Only 'success' status is accepted")
+        return v