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/bus-front.mjs

@@ -0,0 +1,24 @@
+/**
+ * @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: "M4 6 2 7", key: "1mqr15" }],
+  ["path", { d: "M10 6h4", key: "1itunk" }],
+  ["path", { d: "m22 7-2-1", key: "1umjhc" }],
+  ["rect", { width: "16", height: "16", x: "4", y: "3", rx: "2", key: "1wxw4b" }],
+  ["path", { d: "M4 11h16", key: "mpoxn0" }],
+  ["path", { d: "M8 15h.01", key: "a7atzg" }],
+  ["path", { d: "M16 15h.01", key: "rnfrdf" }],
+  ["path", { d: "M6 19v2", key: "1loha6" }],
+  ["path", { d: "M18 21v-2", key: "sqyl04" }]
+];
+const BusFront = createLucideIcon("bus-front", __iconNode);
+
+export { __iconNode, BusFront as default };
+//# sourceMappingURL=bus-front.mjs.map