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/drumstick.mjs

@@ -0,0 +1,26 @@
+/**
+ * @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: "M15.4 15.63a7.875 6 135 1 1 6.23-6.23 4.5 3.43 135 0 0-6.23 6.23", key: "1dtqwm" }
+  ],
+  [
+    "path",
+    {
+      d: "m8.29 12.71-2.6 2.6a2.5 2.5 0 1 0-1.65 4.65A2.5 2.5 0 1 0 8.7 18.3l2.59-2.59",
+      key: "1oq1fw"
+    }
+  ]
+];
+const Drumstick = createLucideIcon("drumstick", __iconNode);
+
+export { __iconNode, Drumstick as default };
+//# sourceMappingURL=drumstick.mjs.map