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/wand.mjs

@@ -0,0 +1,24 @@
+/**
+ * @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: "M15 4V2", key: "z1p9b7" }],
+  ["path", { d: "M15 16v-2", key: "px0unx" }],
+  ["path", { d: "M8 9h2", key: "1g203m" }],
+  ["path", { d: "M20 9h2", key: "19tzq7" }],
+  ["path", { d: "M17.8 11.8 19 13", key: "yihg8r" }],
+  ["path", { d: "M15 9h.01", key: "x1ddxp" }],
+  ["path", { d: "M17.8 6.2 19 5", key: "fd4us0" }],
+  ["path", { d: "m3 21 9-9", key: "1jfql5" }],
+  ["path", { d: "M12.2 6.2 11 5", key: "i3da3b" }]
+];
+const Wand = createLucideIcon("wand", __iconNode);
+
+export { __iconNode, Wand as default };
+//# sourceMappingURL=wand.mjs.map