fix(work-orders): show duplicate-WO copy for edit conflicts (SH-375)

A duplicate work order number edit returns 422 DuplicateWoNumber from the
board PATCH endpoint, which mapped to the generic save-failed copy. Add the
code to the known validation copy map so edits reuse the same duplicate-WO
product text as create, and share the message constant across both paths.

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

@@ -1,12 +1,12 @@
 import { isHTTPError, isNetworkError, isTimeoutError } from "ky";
 import { mapHttpStatusToMessage } from "@/api/api-error";
-import { DISPATCH_REQUIRED_MESSAGE } from "@/domain/work-orders/errors/board-patch-errors";
+import {
+  DISPATCH_REQUIRED_MESSAGE,
+  DUPLICATE_WO_NUMBER_MESSAGE,
+} from "@/domain/work-orders/errors/board-patch-errors";
 
 export const BOARD_CREATE_FAILED_MESSAGE = "Unable to create the work order. Please try again.";
 
-const DUPLICATE_WO_NUMBER_MESSAGE =
-  "This work order number is already assigned to another work order.";
-
 /** Statuses whose mapped copy is fixed product text, never the response body. */
 const FIXED_COPY_STATUSES = new Set([401, 403, 404, 500]);
 

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

@@ -31,9 +31,15 @@ export const BOARD_PATCH_FAILED_MESSAGE = "Unable to save the work order. Please
 export const NO_PERSISTABLE_FIELDS_MESSAGE =
   "These changes cannot be saved on the board. Refresh and edit a supported field.";
 
+export const DUPLICATE_WO_NUMBER_MESSAGE =
+  "This work order number is already assigned to another work order.";
+
 const KNOWN_VALIDATION_COPY: ReadonlyMap<string, string> = new Map([
   ["DispatchRequired", DISPATCH_REQUIRED_MESSAGE],
   ["NoPersistableFields", NO_PERSISTABLE_FIELDS_MESSAGE],
+  // why: editing a WO number to one that already exists returns 422 DuplicateWoNumber;
+  // show the same product copy as create, not the generic save-failed fallback.
+  ["DuplicateWoNumber", DUPLICATE_WO_NUMBER_MESSAGE],
 ]);
 
 /**

src/test/domain/work-orders/api/work-orders-api.test.ts

@@ -615,6 +615,28 @@ describe("workOrdersApi.patchBoardField", () => {
       }),
     ).rejects.toBeInstanceOf(BoardPatchConflictError);
   });
+
+  it("throws BoardPatchValidationError with DuplicateWoNumber code on 422", async () => {
+    apiPatchFn.mockResolvedValue({
+      ok: false,
+      status: 422,
+      json: async () => ({
+        code: "DuplicateWoNumber",
+        message: "WO number already exists.",
+      }),
+    });
+
+    await expect(
+      workOrdersApi.patchBoardField(10, {
+        field: "woNumber",
+        value: "12345678901",
+        workOrderVersion: "AAAAAAA=",
+      }),
+    ).rejects.toMatchObject({
+      name: "BoardPatchValidationError",
+      code: "DuplicateWoNumber",
+    });
+  });
 });
 
 describe("workOrdersApi.createComment", () => {

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

@@ -0,0 +1,29 @@
+import { describe, expect, it } from "vitest";
+import {
+  BOARD_PATCH_CONFLICT_MESSAGE,
+  BOARD_PATCH_FAILED_MESSAGE,
+  BoardPatchConflictError,
+  BoardPatchValidationError,
+  DUPLICATE_WO_NUMBER_MESSAGE,
+  boardPatchErrorMessage,
+} from "@/domain/work-orders/errors/board-patch-errors";
+
+describe("boardPatchErrorMessage", () => {
+  it("maps a DuplicateWoNumber validation error to the duplicate-WO product copy", () => {
+    const error = new BoardPatchValidationError("DuplicateWoNumber", "WO number already exists.");
+
+    expect(boardPatchErrorMessage(error)).toBe(DUPLICATE_WO_NUMBER_MESSAGE);
+  });
+
+  it("never leaks backend validation text for unknown codes", () => {
+    const error = new BoardPatchValidationError("SomethingElse", "vendorId is required.");
+
+    expect(boardPatchErrorMessage(error)).toBe(BOARD_PATCH_FAILED_MESSAGE);
+  });
+
+  it("maps a conflict error to the concurrent-edit copy", () => {
+    const error = new BoardPatchConflictError("stale", null);
+
+    expect(boardPatchErrorMessage(error)).toBe(BOARD_PATCH_CONFLICT_MESSAGE);
+  });
+});