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/vegan.mjs

@@ -0,0 +1,18 @@
+/**
+ * @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: "M16 8q6 0 6-6-6 0-6 6", key: "qsyyc4" }],
+  ["path", { d: "M17.41 3.59a10 10 0 1 0 3 3", key: "41m9h7" }],
+  ["path", { d: "M2 2a26.6 26.6 0 0 1 10 20c.9-6.82 1.5-9.5 4-14", key: "qiv7li" }]
+];
+const Vegan = createLucideIcon("vegan", __iconNode);
+
+export { __iconNode, Vegan as default };
+//# sourceMappingURL=vegan.mjs.map