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/car-taxi-front.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 2h4", key: "n1abiw" }],
+  [
+    "path",
+    { d: "m21 8-2 2-1.5-3.7A2 2 0 0 0 15.646 5H8.4a2 2 0 0 0-1.903 1.257L5 10 3 8", key: "1imjwt" }
+  ],
+  ["path", { d: "M7 14h.01", key: "1qa3f1" }],
+  ["path", { d: "M17 14h.01", key: "7oqj8z" }],
+  ["rect", { width: "18", height: "8", x: "3", y: "10", rx: "2", key: "a7itu8" }],
+  ["path", { d: "M5 18v2", key: "ppbyun" }],
+  ["path", { d: "M19 18v2", key: "gy7782" }]
+];
+const CarTaxiFront = createLucideIcon("car-taxi-front", __iconNode);
+
+export { __iconNode, CarTaxiFront as default };
+//# sourceMappingURL=car-taxi-front.mjs.map