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/gift.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 = [
+  ["path", { d: "M12 7v14", key: "1akyts" }],
+  ["path", { d: "M20 11v8a2 2 0 0 1-2 2H6a2 2 0 0 1-2-2v-8", key: "1sqzm4" }],
+  [
+    "path",
+    { d: "M7.5 7a1 1 0 0 1 0-5A4.8 8 0 0 1 12 7a4.8 8 0 0 1 4.5-5 1 1 0 0 1 0 5", key: "kc0143" }
+  ],
+  ["rect", { x: "3", y: "7", width: "18", height: "4", rx: "1", key: "1hberx" }]
+];
+const Gift = createLucideIcon("gift", __iconNode);
+
+export { __iconNode, Gift as default };
+//# sourceMappingURL=gift.mjs.map