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-pen.mjs

@@ -0,0 +1,29 @@
+/**
+ * @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: "M2 11.5V5a2 2 0 0 1 2-2h3.9c.7 0 1.3.3 1.7.9l.8 1.2c.4.6 1 .9 1.7.9H20a2 2 0 0 1 2 2v10a2 2 0 0 1-2 2h-9.5",
+      key: "a8xqs0"
+    }
+  ],
+  [
+    "path",
+    {
+      d: "M11.378 13.626a1 1 0 1 0-3.004-3.004l-5.01 5.012a2 2 0 0 0-.506.854l-.837 2.87a.5.5 0 0 0 .62.62l2.87-.837a2 2 0 0 0 .854-.506z",
+      key: "1saktj"
+    }
+  ]
+];
+const FolderPen = createLucideIcon("folder-pen", __iconNode);
+
+export { __iconNode, FolderPen as default };
+//# sourceMappingURL=folder-pen.mjs.map