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/spline-pointer.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: "M12.034 12.681a.498.498 0 0 1 .647-.647l9 3.5a.5.5 0 0 1-.033.943l-3.444 1.068a1 1 0 0 0-.66.66l-1.067 3.443a.5.5 0 0 1-.943.033z",
+      key: "xwnzip"
+    }
+  ],
+  ["path", { d: "M5 17A12 12 0 0 1 17 5", key: "1okkup" }],
+  ["circle", { cx: "19", cy: "5", r: "2", key: "mhkx31" }],
+  ["circle", { cx: "5", cy: "19", r: "2", key: "v8kfzx" }]
+];
+const SplinePointer = createLucideIcon("spline-pointer", __iconNode);
+
+export { __iconNode, SplinePointer as default };
+//# sourceMappingURL=spline-pointer.mjs.map