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/hotel.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: "M10 22v-6.57", key: "1wmca3" }],
+  ["path", { d: "M12 11h.01", key: "z322tv" }],
+  ["path", { d: "M12 7h.01", key: "1ivr5q" }],
+  ["path", { d: "M14 15.43V22", key: "1q2vjd" }],
+  ["path", { d: "M15 16a5 5 0 0 0-6 0", key: "o9wqvi" }],
+  ["path", { d: "M16 11h.01", key: "xkw8gn" }],
+  ["path", { d: "M16 7h.01", key: "1kdx03" }],
+  ["path", { d: "M8 11h.01", key: "1dfujw" }],
+  ["path", { d: "M8 7h.01", key: "1vti4s" }],
+  ["rect", { x: "4", y: "2", width: "16", height: "20", rx: "2", key: "1uxh74" }]
+];
+const Hotel = createLucideIcon("hotel", __iconNode);
+
+export { __iconNode, Hotel as default };
+//# sourceMappingURL=hotel.mjs.map