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/chef-hat.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: "M17 21a1 1 0 0 0 1-1v-5.35c0-.457.316-.844.727-1.041a4 4 0 0 0-2.134-7.589 5 5 0 0 0-9.186 0 4 4 0 0 0-2.134 7.588c.411.198.727.585.727 1.041V20a1 1 0 0 0 1 1Z",
+      key: "1qvrer"
+    }
+  ],
+  ["path", { d: "M6 17h12", key: "1jwigz" }]
+];
+const ChefHat = createLucideIcon("chef-hat", __iconNode);
+
+export { __iconNode, ChefHat as default };
+//# sourceMappingURL=chef-hat.mjs.map