Add sync error logging, extend error flash, fix unload saves

- Log workforce sync errors to backend stdout so they appear in docker logs
- Extend error flash from 5s to 15s so errors are readable
- Replace sendBeacon (POST-only) with keepalive fetch (PUT) on unload —
  sendBeacon was hitting 404s on all three unload saves

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

frontend/node_modules/lucide-react/dist/esm/icons/mouse-pointer.mjs

@@ -0,0 +1,23 @@
+/**
+ * @license lucide-react v1.24.0 - ISC
+ *
+ * This source code is licensed under the ISC license.
+ * See the LICENSE file in the root directory of this source tree.
+ */
+
+import createLucideIcon from '../createLucideIcon.mjs';
+
+const __iconNode = [
+  ["path", { d: "M12.586 12.586 19 19", key: "ea5xo7" }],
+  [
+    "path",
+    {
+      d: "M3.688 3.037a.497.497 0 0 0-.651.651l6.5 15.999a.501.501 0 0 0 .947-.062l1.569-6.083a2 2 0 0 1 1.448-1.479l6.124-1.579a.5.5 0 0 0 .063-.947z",
+      key: "277e5u"
+    }
+  ]
+];
+const MousePointer = createLucideIcon("mouse-pointer", __iconNode);
+
+export { __iconNode, MousePointer as default };
+//# sourceMappingURL=mouse-pointer.mjs.map