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/banana.mjs

@@ -0,0 +1,23 @@
+/**
+ * @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: "M4 13c3.5-2 8-2 10 2a5.5 5.5 0 0 1 8 5", key: "1cscit" }],
+  [
+    "path",
+    {
+      d: "M5.15 17.89c5.52-1.52 8.65-6.89 7-12C11.55 4 11.5 2 13 2c3.22 0 5 5.5 5 8 0 6.5-4.2 12-10.49 12C5.11 22 2 22 2 20c0-1.5 1.14-1.55 3.15-2.11Z",
+      key: "1y1nbv"
+    }
+  ]
+];
+const Banana = createLucideIcon("banana", __iconNode);
+
+export { __iconNode, Banana as default };
+//# sourceMappingURL=banana.mjs.map