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/shrub.mjs

@@ -0,0 +1,18 @@
+/**
+ * @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 22v-5.172a2 2 0 0 0-.586-1.414L9.5 13.5", key: "1p17fm" }],
+  ["path", { d: "M14.5 14.5 12 17", key: "dy5w4y" }],
+  ["path", { d: "M17 8.8A6 6 0 0 1 13.8 20H10A6.5 6.5 0 0 1 7 8a5 5 0 0 1 10 0z", key: "6z7b3o" }]
+];
+const Shrub = createLucideIcon("shrub", __iconNode);
+
+export { __iconNode, Shrub as default };
+//# sourceMappingURL=shrub.mjs.map