fix(work-orders): show fixed copy for edit conflict toasts (SH-375)

src/domain/work-orders/errors/board-patch-errors.ts

@@ -44,6 +44,9 @@ export function boardPatchValidationMessage(error: BoardPatchValidationError): s
   return KNOWN_VALIDATION_COPY.get(error.code) ?? BOARD_PATCH_FAILED_MESSAGE;
 }
 
+export const BOARD_PATCH_CONFLICT_MESSAGE =
+  "This work order was changed by someone else. Refresh to see the latest before saving again.";
+
 export const PARTIAL_SAVE_PREFIX = "Some changes were saved, but the rest were not.";
 
 /** Statuses whose mapped copy is fixed product text, never the response body. */
@@ -51,6 +54,9 @@ const FIXED_COPY_STATUSES = new Set([401, 403, 404, 500]);
 
 /** why: any board edit failure toast must use product copy, never backend text or field keys. */
 export function boardPatchErrorMessage(error: unknown): string {
+  if (error instanceof BoardPatchConflictError) {
+    return BOARD_PATCH_CONFLICT_MESSAGE;
+  }
   if (error instanceof BoardPatchValidationError) {
     return boardPatchValidationMessage(error);
   }

src/domain/work-orders/use-cases/use-work-order-table-mutations.ts

@@ -156,7 +156,7 @@ export function useWorkOrderTableMutations(
 
       if (error instanceof BoardPatchConflictError && error.currentState) {
         onPatch(id, error.currentState);
-        toast.error(error.message || "Conflict — refreshed with latest data");
+        toast.error(boardPatchErrorMessage(error));
       } else {
         clearPatch(id);
         toast.error(boardPatchErrorMessage(error));

src/test/domain/work-orders/use-cases/use-work-order-table-mutations-errors.test.tsx

@@ -4,6 +4,7 @@ import type { ReactNode } from "react";
 import { toast } from "react-toastify";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import {
+  BOARD_PATCH_CONFLICT_MESSAGE,
   BOARD_PATCH_FAILED_MESSAGE,
   DISPATCH_REQUIRED_MESSAGE,
   PARTIAL_SAVE_PREFIX,
@@ -142,4 +143,29 @@ describe("useWorkOrderTableMutations edit error copy", () => {
 
     expect(message).toBe(`${PARTIAL_SAVE_PREFIX} ${DISPATCH_REQUIRED_MESSAGE}`);
   });
+
+  it("shows fixed conflict copy and still applies the latest row on a 409", async () => {
+    const onPatch = vi.fn();
+    respondWith({
+      status: 409,
+      body: {
+        message: "RowVersion mismatch for workOrderId 7 (expected v1, found v3).",
+        currentState: { id: 7, workOrderNumber: "WO-099", rowVersion: "v3" },
+      },
+    });
+
+    const message = await patchAndGetToast({ woNumber: "WO-100" }, 1, onPatch);
+
+    expect(message).toBe(BOARD_PATCH_CONFLICT_MESSAGE);
+    expect(message).not.toMatch(/RowVersion|workOrderId|v3/);
+    expect(onPatch).toHaveBeenLastCalledWith(7, expect.objectContaining({ rowVersion: "v3" }));
+  });
+
+  it("shows fixed conflict copy when a 409 carries no latest row", async () => {
+    respondWith({ status: 409, body: { message: "RowVersion mismatch for workOrderId 7." } });
+
+    const message = await patchAndGetToast();
+
+    expect(message).toBe(BOARD_PATCH_CONFLICT_MESSAGE);
+  });
 });