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/carrot.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 16a1 1 0 0 0-7-7q-4 4-5.987 12.385a.5.5 0 0 0 .602.602Q11 20 15 16l-3-3",
+      key: "1ta62j"
+    }
+  ],
+  ["path", { d: "M15 9q4 4 7 0-3-4-7 0 4-4 0-7-4 3 0 7", key: "1svf7i" }],
+  ["path", { d: "m8 15-2.58-2.58", key: "7t238r" }]
+];
+const Carrot = createLucideIcon("carrot", __iconNode);
+
+export { __iconNode, Carrot as default };
+//# sourceMappingURL=carrot.mjs.map