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/flashlight-off.mjs

@@ -0,0 +1,29 @@
+/**
+ * @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: "M11.652 6H18", key: "voqkpr" }],
+  ["path", { d: "M12 13v1", key: "176q98" }],
+  [
+    "path",
+    {
+      d: "M16 16v4a2 2 0 0 1-2 2h-4a2 2 0 0 1-2-2v-8a4 4 0 0 0-.8-2.4l-.6-.8A3 3 0 0 1 6 7V6",
+      key: "dzyf92"
+    }
+  ],
+  ["path", { d: "m2 2 20 20", key: "1ooewy" }],
+  [
+    "path",
+    { d: "M7.649 2H17a1 1 0 0 1 1 1v4a3 3 0 0 1-.6 1.8l-.6.8a4 4 0 0 0-.55 1.007", key: "1hvcfn" }
+  ]
+];
+const FlashlightOff = createLucideIcon("flashlight-off", __iconNode);
+
+export { __iconNode, FlashlightOff as default };
+//# sourceMappingURL=flashlight-off.mjs.map