fix(kitchen-service): harden derived ticket identities

docs/api/internal-kitchen-workflows.md

@@ -18,6 +18,7 @@ This repo now orchestrates kitchen progression over persisted kitchen tickets fr
 
 That means:
 - board and queue reads come from persisted kitchen tickets plus lifecycle-derived ticket materialization for newly accepted restaurant orders
+- derived kitchen IDs now use the full order identity so runtime projections stay collision-safe across similar order numbers
 - claim and priority changes update persisted kitchen ticket state
 - ticket transitions update both kitchen tickets and the linked restaurant order lifecycle
 - accepted orders can become kitchen-visible without waiting for a stack reset or a second write path

src/Kitchen.Service.Application/Ports/DefaultKitchenWorkflowPort.cs

@@ -316,10 +316,9 @@ public sealed class DefaultKitchenWorkflowPort : IKitchenWorkflowPort
 
     private static PersistedKitchenWorkItemRecord BuildDerivedWorkItem(PersistedRestaurantLifecycleRecord order)
     {
-        var numericSuffix = new string(order.OrderId.Where(char.IsDigit).ToArray());
-        var workItemId = string.IsNullOrWhiteSpace(numericSuffix)
-            ? $"WK-{order.OrderId}"
-            : $"WK-{numericSuffix}";
+        // Use the full order identity when deriving kitchen IDs so distinct orders
+        // cannot collide just because they share a numeric suffix.
+        var workItemId = $"WK-{order.OrderId}";
 
         return new PersistedKitchenWorkItemRecord(
             order.ContextId,

tests/Kitchen.Service.Application.UnitTests/KitchenWorkflowUseCasesTests.cs

@@ -56,6 +56,53 @@ public class KitchenWorkflowUseCasesTests
 
         Assert.Equal("hot-line", derivedItem.Station);
         Assert.Equal("Queued", derivedItem.State);
+        Assert.Equal("WK-ORD-1099", derivedItem.WorkItemId);
+        Assert.Equal("KT-ORD-1099", derivedItem.TicketId);
+    }
+
+    [Fact]
+    public async Task GetKitchenBoardUseCase_DerivesCollisionSafeIdsForSimilarNumericSuffixes()
+    {
+        await restaurantLifecycle.UpsertOrderAsync(
+            new Kitchen.Service.Application.State.PersistedRestaurantLifecycleRecord(
+                "demo-context",
+                "ORD-STAGE49-001",
+                "CHK-ORD-STAGE49-001",
+                "T-31",
+                "Accepted",
+                "Open",
+                2,
+                false,
+                25.00m,
+                "USD",
+                "customer-orders",
+                new[] { "ITEM-101", "ITEM-102" },
+                DateTime.UtcNow),
+            CancellationToken.None);
+
+        await restaurantLifecycle.UpsertOrderAsync(
+            new Kitchen.Service.Application.State.PersistedRestaurantLifecycleRecord(
+                "demo-context",
+                "ORD-STAGE49-WAITER-001",
+                "CHK-ORD-STAGE49-WAITER-001",
+                "T-32",
+                "Accepted",
+                "Open",
+                3,
+                false,
+                37.50m,
+                "USD",
+                "waiter-floor",
+                new[] { "ITEM-201", "ITEM-202", "ITEM-203" },
+                DateTime.UtcNow.AddSeconds(1)),
+            CancellationToken.None);
+
+        var useCase = new GetKitchenBoardUseCase(workflowPort);
+        var response = await useCase.HandleAsync(new GetKitchenBoardRequest("demo-context"), CancellationToken.None);
+        var queuedLane = Assert.Single(response.Lanes, lane => lane.Lane == "queued");
+
+        Assert.Contains(queuedLane.Items, item => item.WorkItemId == "WK-ORD-STAGE49-001" && item.TicketId == "KT-ORD-STAGE49-001");
+        Assert.Contains(queuedLane.Items, item => item.WorkItemId == "WK-ORD-STAGE49-WAITER-001" && item.TicketId == "KT-ORD-STAGE49-WAITER-001");
     }
 
     [Fact]