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/move.mjs

@@ -0,0 +1,21 @@
+/**
+ * @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 2v20", key: "t6zp3m" }],
+  ["path", { d: "m15 19-3 3-3-3", key: "11eu04" }],
+  ["path", { d: "m19 9 3 3-3 3", key: "1mg7y2" }],
+  ["path", { d: "M2 12h20", key: "9i4pu4" }],
+  ["path", { d: "m5 9-3 3 3 3", key: "j64kie" }],
+  ["path", { d: "m9 5 3-3 3 3", key: "l8vdw6" }]
+];
+const Move = createLucideIcon("move", __iconNode);
+
+export { __iconNode, Move as default };
+//# sourceMappingURL=move.mjs.map