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/user-x.mjs

@@ -0,0 +1,19 @@
+/**
+ * @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: "M16 21v-2a4 4 0 0 0-4-4H6a4 4 0 0 0-4 4v2", key: "1yyitq" }],
+  ["circle", { cx: "9", cy: "7", r: "4", key: "nufk8" }],
+  ["line", { x1: "17", x2: "22", y1: "8", y2: "13", key: "3nzzx3" }],
+  ["line", { x1: "22", x2: "17", y1: "8", y2: "13", key: "1swrse" }]
+];
+const UserX = createLucideIcon("user-x", __iconNode);
+
+export { __iconNode, UserX as default };
+//# sourceMappingURL=user-x.mjs.map