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/chart-pie.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: "M21 12c.552 0 1.005-.449.95-.998a10 10 0 0 0-8.953-8.951c-.55-.055-.998.398-.998.95v8a1 1 0 0 0 1 1z",
+      key: "pzmjnu"
+    }
+  ],
+  ["path", { d: "M21.21 15.89A10 10 0 1 1 8 2.83", key: "k2fpak" }]
+];
+const ChartPie = createLucideIcon("chart-pie", __iconNode);
+
+export { __iconNode, ChartPie as default };
+//# sourceMappingURL=chart-pie.mjs.map