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/shirt.mjs

@@ -0,0 +1,22 @@
+/**
+ * @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: "M20.38 3.46 16 2a4 4 0 0 1-8 0L3.62 3.46a2 2 0 0 0-1.34 2.23l.58 3.47a1 1 0 0 0 .99.84H6v10c0 1.1.9 2 2 2h8a2 2 0 0 0 2-2V10h2.15a1 1 0 0 0 .99-.84l.58-3.47a2 2 0 0 0-1.34-2.23z",
+      key: "1wgbhj"
+    }
+  ]
+];
+const Shirt = createLucideIcon("shirt", __iconNode);
+
+export { __iconNode, Shirt as default };
+//# sourceMappingURL=shirt.mjs.map