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/bean.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: "M10.165 6.598C9.954 7.478 9.64 8.36 9 9c-.64.64-1.521.954-2.402 1.165A6 6 0 0 0 8 22c7.732 0 14-6.268 14-14a6 6 0 0 0-11.835-1.402Z",
+      key: "1tvzk7"
+    }
+  ],
+  ["path", { d: "M5.341 10.62a4 4 0 1 0 5.279-5.28", key: "2cyri2" }]
+];
+const Bean = createLucideIcon("bean", __iconNode);
+
+export { __iconNode, Bean as default };
+//# sourceMappingURL=bean.mjs.map