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/package-2.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: "M12 3v6", key: "1holv5" }],
+  [
+    "path",
+    {
+      d: "M16.76 3a2 2 0 0 1 1.8 1.1l2.23 4.479a2 2 0 0 1 .21.891V19a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V9.472a2 2 0 0 1 .211-.894L5.45 4.1A2 2 0 0 1 7.24 3z",
+      key: "187q7i"
+    }
+  ],
+  ["path", { d: "M3.054 9.013h17.893", key: "grwhos" }]
+];
+const Package2 = createLucideIcon("package-2", __iconNode);
+
+export { __iconNode, Package2 as default };
+//# sourceMappingURL=package-2.mjs.map