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/aperture.mjs

@@ -0,0 +1,22 @@
+/**
+ * @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 = [
+  ["circle", { cx: "12", cy: "12", r: "10", key: "1mglay" }],
+  ["path", { d: "m14.31 8 5.74 9.94", key: "1y6ab4" }],
+  ["path", { d: "M9.69 8h11.48", key: "1wxppr" }],
+  ["path", { d: "m7.38 12 5.74-9.94", key: "1grp0k" }],
+  ["path", { d: "M9.69 16 3.95 6.06", key: "libnyf" }],
+  ["path", { d: "M14.31 16H2.83", key: "x5fava" }],
+  ["path", { d: "m16.62 12-5.74 9.94", key: "1vwawt" }]
+];
+const Aperture = createLucideIcon("aperture", __iconNode);
+
+export { __iconNode, Aperture as default };
+//# sourceMappingURL=aperture.mjs.map