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/plane-landing.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: "M2 22h20", key: "272qi7" }],
+  [
+    "path",
+    {
+      d: "M3.77 10.77 2 9l2-4.5 1.1.55c.55.28.9.84.9 1.45s.35 1.17.9 1.45L8 8.5l3-6 1.05.53a2 2 0 0 1 1.09 1.52l.72 5.4a2 2 0 0 0 1.09 1.52l4.4 2.2c.42.22.78.55 1.01.96l.6 1.03c.49.88-.06 1.98-1.06 2.1l-1.18.15c-.47.06-.95-.02-1.37-.24L4.29 11.15a2 2 0 0 1-.52-.38Z",
+      key: "1ma21e"
+    }
+  ]
+];
+const PlaneLanding = createLucideIcon("plane-landing", __iconNode);
+
+export { __iconNode, PlaneLanding as default };
+//# sourceMappingURL=plane-landing.mjs.map