feat(allocations): add Excel export button to allocations toolbar

Adds an Export button that downloads visible/filtered allocation rows
as an xlsx file via the existing downloadWorkbookSheets utility.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/components/allocations/AllocationsClient.tsx

@@ -25,6 +25,7 @@ import { ALLOCATION_STATUS_BADGE as STATUS_BADGE } from "~/lib/status-styles.js"
 import { SuccessToast } from "~/components/ui/SuccessToast.js";
 import { EmptyState } from "~/components/ui/EmptyState.js";
 import { BatchDateShiftModal } from "./BatchDateShiftModal.js";
+import { downloadWorkbookSheets } from "~/lib/workbook-export.js";
 import {
   collapseAllAllocationGroups,
   createInitialCollapsedAllocationGroups,
@@ -191,6 +192,22 @@ export function AllocationsClient() {
   // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [filterProjectId, filterResourceId, filterStatus, hidePastProjects, hideCompletedProjects, hideDraftProjects]);
 
+  function handleExportExcel() {
+    const rows: (string | number | null)[][] = [
+      ["Resource", "Project", "Role", "Start Date", "End Date", "Hours/Day", "Status"],
+      ...sorted.map((a) => [
+        (a.resource as { displayName?: string } | null | undefined)?.displayName ?? "Unassigned",
+        (a.project as { shortCode?: string; name?: string } | null | undefined) ? `${(a.project as { shortCode: string }).shortCode} — ${(a.project as { name: string }).name}` : "",
+        a.role ?? "",
+        typeof a.startDate === "string" ? a.startDate : (a.startDate as Date).toISOString().slice(0, 10),
+        typeof a.endDate === "string" ? a.endDate : (a.endDate as Date).toISOString().slice(0, 10),
+        a.hoursPerDay,
+        a.status,
+      ]),
+    ];
+    void downloadWorkbookSheets("allocations.xlsx", [{ name: "Allocations", rows }]);
+  }
+
   function openCreate() {
     setEditingAllocation(null);
     setModalOpen(true);
@@ -665,6 +682,20 @@ export function AllocationsClient() {
           </button>
         </div>
 
+        {sorted.length > 0 && (
+          <button
+            type="button"
+            onClick={handleExportExcel}
+            title="Export visible rows to Excel"
+            className="inline-flex items-center gap-1.5 rounded-lg border border-gray-300 dark:border-gray-600 px-2.5 py-2 text-sm font-medium text-gray-600 dark:text-gray-300 transition hover:border-gray-400 hover:bg-gray-50 dark:hover:bg-gray-800"
+          >
+            <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-4l-4 4m0 0l-4-4m4 4V4" />
+            </svg>
+            Export
+          </button>
+        )}
+
         {viewMode === "grouped" && groups.length > 1 && (
           <div className="flex items-center gap-1">
             <button type="button" onClick={expandAll} className="text-xs text-brand-600 hover:text-brand-800 dark:text-brand-400 dark:hover:text-brand-200 whitespace-nowrap">