fix: add missing webhook payload types to validation

Add the following webhook payload types that were missing from the
WebhoookPayload union used for webhook validation:

- WebhookCustomerSeatAssignedPayload (customer_seat.assigned)
- WebhookCustomerSeatClaimedPayload (customer_seat.claimed)
- WebhookCustomerSeatRevokedPayload (customer_seat.revoked)
- WebhookSubscriptionPastDuePayload (subscription.past_due)

These payload models already exist in the SDK but were not included
in the webhook validation discriminated union, causing validation
errors when receiving these webhook events.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: psincraian

src/polar_sdk/_webhooks/__init__.py

@@ -18,6 +18,9 @@
     WebhookCheckoutUpdatedPayload,
     WebhookCustomerCreatedPayload,
     WebhookCustomerDeletedPayload,
+    WebhookCustomerSeatAssignedPayload,
+    WebhookCustomerSeatClaimedPayload,
+    WebhookCustomerSeatRevokedPayload,
     WebhookCustomerStateChangedPayload,
     WebhookCustomerUpdatedPayload,
     WebhookOrderCreatedPayload,
@@ -32,6 +35,7 @@
     WebhookSubscriptionActivePayload,
     WebhookSubscriptionCanceledPayload,
     WebhookSubscriptionCreatedPayload,
+    WebhookSubscriptionPastDuePayload,
     WebhookSubscriptionRevokedPayload,
     WebhookSubscriptionUncanceledPayload,
     WebhookSubscriptionUpdatedPayload,
@@ -52,6 +56,9 @@ def _get_discriminator(v: Any) -> Union[str, None]:
         Annotated[WebhookCustomerUpdatedPayload, Tag("customer.updated")],
         Annotated[WebhookCustomerDeletedPayload, Tag("customer.deleted")],
         Annotated[WebhookCustomerStateChangedPayload, Tag("customer.state_changed")],
+        Annotated[WebhookCustomerSeatAssignedPayload, Tag("customer_seat.assigned")],
+        Annotated[WebhookCustomerSeatClaimedPayload, Tag("customer_seat.claimed")],
+        Annotated[WebhookCustomerSeatRevokedPayload, Tag("customer_seat.revoked")],
         Annotated[WebhookOrderCreatedPayload, Tag("order.created")],
         Annotated[WebhookOrderUpdatedPayload, Tag("order.updated")],
         Annotated[WebhookOrderPaidPayload, Tag("order.paid")],
@@ -62,6 +69,7 @@ def _get_discriminator(v: Any) -> Union[str, None]:
         Annotated[WebhookSubscriptionCanceledPayload, Tag("subscription.canceled")],
         Annotated[WebhookSubscriptionUncanceledPayload, Tag("subscription.uncanceled")],
         Annotated[WebhookSubscriptionRevokedPayload, Tag("subscription.revoked")],
+        Annotated[WebhookSubscriptionPastDuePayload, Tag("subscription.past_due")],
         Annotated[WebhookRefundCreatedPayload, Tag("refund.created")],
         Annotated[WebhookRefundUpdatedPayload, Tag("refund.updated")],
         Annotated[WebhookProductCreatedPayload, Tag("product.created")],