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/birdhouse.mjs

@@ -0,0 +1,21 @@
+/**
+ * @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 18v4", key: "jadmvz" }],
+  ["path", { d: "m17 18 1.956-11.468", key: "l5n2ro" }],
+  ["path", { d: "m3 8 7.82-5.615a2 2 0 0 1 2.36 0L21 8", key: "1sy6n7" }],
+  ["path", { d: "M4 18h16", key: "19g7jn" }],
+  ["path", { d: "M7 18 5.044 6.532", key: "1uqdf2" }],
+  ["circle", { cx: "12", cy: "10", r: "2", key: "1yojzk" }]
+];
+const Birdhouse = createLucideIcon("birdhouse", __iconNode);
+
+export { __iconNode, Birdhouse as default };
+//# sourceMappingURL=birdhouse.mjs.map