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/toolbox.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: "M16 12v4", key: "vf1vip" }],
+  [
+    "path",
+    {
+      d: "M16 6a2 2 0 0 1 1.414.586l4 4A2 2 0 0 1 22 12v7a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2v-7a2 2 0 0 1 .586-1.414l4-4A2 2 0 0 1 8 6z",
+      key: "1h1rvn"
+    }
+  ],
+  ["path", { d: "M16 6V4a2 2 0 0 0-2-2h-4a2 2 0 0 0-2 2v2", key: "1ksdt3" }],
+  ["path", { d: "M2 14h20", key: "myj16y" }],
+  ["path", { d: "M8 12v4", key: "1w4uao" }]
+];
+const Toolbox = createLucideIcon("toolbox", __iconNode);
+
+export { __iconNode, Toolbox as default };
+//# sourceMappingURL=toolbox.mjs.map