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/door-open.mjs

@@ -0,0 +1,26 @@
+/**
+ * @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: "M11 20H2", key: "nlcfvz" }],
+  [
+    "path",
+    {
+      d: "M11 4.562v16.157a1 1 0 0 0 1.242.97L19 20V5.562a2 2 0 0 0-1.515-1.94l-4-1A2 2 0 0 0 11 4.561z",
+      key: "au4z13"
+    }
+  ],
+  ["path", { d: "M11 4H8a2 2 0 0 0-2 2v14", key: "74r1mk" }],
+  ["path", { d: "M14 12h.01", key: "1jfl7z" }],
+  ["path", { d: "M22 20h-3", key: "vhrsz" }]
+];
+const DoorOpen = createLucideIcon("door-open", __iconNode);
+
+export { __iconNode, DoorOpen as default };
+//# sourceMappingURL=door-open.mjs.map