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/folder-archive.mjs

@@ -0,0 +1,25 @@
+/**
+ * @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 = [
+  ["circle", { cx: "15", cy: "19", r: "2", key: "u2pros" }],
+  [
+    "path",
+    {
+      d: "M20.9 19.8A2 2 0 0 0 22 18V8a2 2 0 0 0-2-2h-7.9a2 2 0 0 1-1.69-.9L9.6 3.9A2 2 0 0 0 7.93 3H4a2 2 0 0 0-2 2v13a2 2 0 0 0 2 2h5.1",
+      key: "1jj40k"
+    }
+  ],
+  ["path", { d: "M15 11v-1", key: "cntcp" }],
+  ["path", { d: "M15 17v-2", key: "1279jj" }]
+];
+const FolderArchive = createLucideIcon("folder-archive", __iconNode);
+
+export { __iconNode, FolderArchive as default };
+//# sourceMappingURL=folder-archive.mjs.map