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/wifi-cog.mjs

@@ -0,0 +1,27 @@
+/**
+ * @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: "m14.305 19.53.923-.382", key: "3m78fa" }],
+  ["path", { d: "m15.228 16.852-.923-.383", key: "npixar" }],
+  ["path", { d: "m16.852 15.228-.383-.923", key: "5xggr7" }],
+  ["path", { d: "m16.852 20.772-.383.924", key: "dpfhf9" }],
+  ["path", { d: "m19.148 15.228.383-.923", key: "1reyyz" }],
+  ["path", { d: "m19.53 21.696-.382-.924", key: "1goivc" }],
+  ["path", { d: "M2 7.82a15 15 0 0 1 20 0", key: "1ovjuk" }],
+  ["path", { d: "m20.772 16.852.924-.383", key: "htqkph" }],
+  ["path", { d: "m20.772 19.148.924.383", key: "9w9pjp" }],
+  ["path", { d: "M5 11.858a10 10 0 0 1 11.5-1.785", key: "3sn16i" }],
+  ["path", { d: "M8.5 15.429a5 5 0 0 1 2.413-1.31", key: "1pxovh" }],
+  ["circle", { cx: "18", cy: "18", r: "3", key: "1xkwt0" }]
+];
+const WifiCog = createLucideIcon("wifi-cog", __iconNode);
+
+export { __iconNode, WifiCog as default };
+//# sourceMappingURL=wifi-cog.mjs.map