add function to apply mutations over grpc

proto/control_plane.proto

@@ -4,6 +4,8 @@ package messages;
 
 option go_package = "git.k6n.net/go-cart-actor/proto;messages";
 
+import "messages.proto";
+
 // -----------------------------------------------------------------------------
 // Control Plane gRPC API
 // -----------------------------------------------------------------------------
@@ -65,6 +67,16 @@ message ExpiryAnnounce {
   repeated uint64 ids = 2;
 }
 
+message ApplyRequest {
+
+    uint64 id = 1;
+    repeated Mutation messages = 2;
+}
+
+message ApplyResult {
+  bool accepted = 1;
+}
+
 // ControlPlane defines cluster coordination and ownership operations.
 service ControlPlane {
   // Ping for liveness; lightweight health signal.
@@ -80,6 +92,7 @@ service ControlPlane {
 
   // Ownership announcement: first-touch claim broadcast (idempotent; best-effort).
   rpc AnnounceOwnership(OwnershipAnnounce) returns (OwnerChangeAck);
+  rpc Apply(ApplyRequest) returns (ApplyResult);
 
   // Expiry announcement: drop remote ownership hints when local TTL expires.
   rpc AnnounceExpiry(ExpiryAnnounce) returns (OwnerChangeAck);

proto/messages.proto

@@ -171,3 +171,32 @@ message AddGiftcard {
 message RemoveGiftcard {
   uint32 id = 1;
 }
+
+message Mutation {
+  oneof type {
+    ClearCartRequest clear_cart = 1;
+    AddItem add_item = 2;
+    RemoveItem remove_item = 3;
+    ChangeQuantity change_quantity = 4;
+    SetDelivery set_delivery = 5;
+    SetPickupPoint set_pickup_point = 6;
+    RemoveDelivery remove_delivery = 7;
+    SetUserId set_user_id = 8;
+    LineItemMarking line_item_marking = 9;
+    RemoveLineItemMarking remove_line_item_marking = 10;
+    SubscriptionAdded subscription_added = 11;
+    PaymentDeclined payment_declined = 12;
+    ConfirmationViewed confirmation_viewed = 13;
+    CreateCheckoutOrder create_checkout_order = 14;
+    OrderCreated order_created = 15;
+    Noop noop = 16;
+    InitializeCheckout initialize_checkout = 17;
+    InventoryReserved inventory_reserved = 18;
+    AddVoucher add_voucher = 19;
+    RemoveVoucher remove_voucher = 20;
+    UpsertSubscriptionDetails upsert_subscription_details = 21;
+    PreConditionFailed pre_condition_failed = 22;
+    AddGiftcard add_giftcard = 23;
+    RemoveGiftcard remove_giftcard = 24;
+  }
+}