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/bell-check.mjs

@@ -0,0 +1,28 @@
+/**
+ * @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: "M10.268 21a2 2 0 0 0 3.464 0", key: "vwvbt9" }],
+  ["path", { d: "m15 8 2 2 4-4", key: "sbrgsm" }],
+  [
+    "path",
+    { d: "M16.8607 4.4824A6 6 0 0 0 6 8C6 12.499 4.589 13.956 3.262 15.326", key: "qcog4a" }
+  ],
+  [
+    "path",
+    {
+      d: "M3.262 15.326A1 1 0 0 0 4 17H20A1 1 0 0 0 20.74 15.327C20.209 14.779 19.665 14.218 19.203 13.454",
+      key: "mxnnoh"
+    }
+  ]
+];
+const BellCheck = createLucideIcon("bell-check", __iconNode);
+
+export { __iconNode, BellCheck as default };
+//# sourceMappingURL=bell-check.mjs.map