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/pen-off.mjs

@@ -0,0 +1,24 @@
+/**
+ * @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: "m10 10-6.157 6.162a2 2 0 0 0-.5.833l-1.322 4.36a.5.5 0 0 0 .622.624l4.358-1.323a2 2 0 0 0 .83-.5L14 13.982",
+      key: "bjo8r8"
+    }
+  ],
+  ["path", { d: "m12.829 7.172 4.359-4.346a1 1 0 1 1 3.986 3.986l-4.353 4.353", key: "16h5ne" }],
+  ["path", { d: "m2 2 20 20", key: "1ooewy" }]
+];
+const PenOff = createLucideIcon("pen-off", __iconNode);
+
+export { __iconNode, PenOff as default };
+//# sourceMappingURL=pen-off.mjs.map