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/rat.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: "M13 22H4a2 2 0 0 1 0-4h12", key: "bt3f23" }],
+  ["path", { d: "M13.236 18a3 3 0 0 0-2.2-5", key: "1tbvmo" }],
+  ["path", { d: "M16 9h.01", key: "1bdo4e" }],
+  [
+    "path",
+    {
+      d: "M16.82 3.94a3 3 0 1 1 3.237 4.868l1.815 2.587a1.5 1.5 0 0 1-1.5 2.1l-2.872-.453a3 3 0 0 0-3.5 3",
+      key: "9ch7kn"
+    }
+  ],
+  ["path", { d: "M17 4.988a3 3 0 1 0-5.2 2.052A7 7 0 0 0 4 14.015 4 4 0 0 0 8 18", key: "3s7e9i" }]
+];
+const Rat = createLucideIcon("rat", __iconNode);
+
+export { __iconNode, Rat as default };
+//# sourceMappingURL=rat.mjs.map