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/sticky-note-x.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 = [
+  ["path", { d: "M15 3v5a1 1 0 0 0 1 1h5", key: "6s6qgf" }],
+  ["path", { d: "m16 16 5 5", key: "8tpb07" }],
+  [
+    "path",
+    {
+      d: "M21 12V9a2.4 2.4 0 0 0-.706-1.706l-3.588-3.588A2.4 2.4 0 0 0 15 3H5a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h7",
+      key: "156tez"
+    }
+  ],
+  ["path", { d: "m21 16-5 5", key: "kplof2" }]
+];
+const StickyNoteX = createLucideIcon("sticky-note-x", __iconNode);
+
+export { __iconNode, StickyNoteX as default };
+//# sourceMappingURL=sticky-note-x.mjs.map