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/paper-bag.mjs

@@ -0,0 +1,29 @@
+/**
+ * @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: "M5.364 3.848C4 6 3 9.652 3 12.652V19a2 2 0 002 2h14a2 2 0 002-2v-5c0-2.334-1.816-4.668-2.622-7.002",
+      key: "vlsvfu"
+    }
+  ],
+  [
+    "path",
+    {
+      d: "M7 3h11.379a2 2 0 011.789 1.106l.723 1.447A1 1 0 0119.997 7h-8.525a2 2 0 01-1.789-1.106L8.79 4.105a2 2 0 10-3.579 1.789l2.261 4.522A5 5 0 018 12.652V21",
+      key: "12exh5"
+    }
+  ]
+];
+const PaperBag = createLucideIcon("paper-bag", __iconNode);
+
+export { __iconNode, PaperBag as default };
+//# sourceMappingURL=paper-bag.mjs.map