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/helicopter.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: "M11 17v4", key: "14wq8k" }],
+  ["path", { d: "M14 3v8a2 2 0 0 0 2 2h5.865", key: "12oo5h" }],
+  ["path", { d: "M17 17v4", key: "hdt4hh" }],
+  [
+    "path",
+    { d: "M18 17a4 4 0 0 0 4-4 8 6 0 0 0-8-6 6 5 0 0 0-6 5v3a2 2 0 0 0 2 2z", key: "yynif" }
+  ],
+  ["path", { d: "M2 10v5", key: "sa5akn" }],
+  ["path", { d: "M6 3h16", key: "27qw71" }],
+  ["path", { d: "M7 21h14", key: "1ugz0u" }],
+  ["path", { d: "M8 13H2", key: "1thz1o" }]
+];
+const Helicopter = createLucideIcon("helicopter", __iconNode);
+
+export { __iconNode, Helicopter as default };
+//# sourceMappingURL=helicopter.mjs.map