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/shower-head.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: "m4 4 2.5 2.5", key: "uv2vmf" }],
+  ["path", { d: "M13.5 6.5a4.95 4.95 0 0 0-7 7", key: "frdkwv" }],
+  ["path", { d: "M15 5 5 15", key: "1ag8rq" }],
+  ["path", { d: "M14 17v.01", key: "eokfpp" }],
+  ["path", { d: "M10 16v.01", key: "14uyyl" }],
+  ["path", { d: "M13 13v.01", key: "1v1k97" }],
+  ["path", { d: "M16 10v.01", key: "5169yg" }],
+  ["path", { d: "M11 20v.01", key: "cj92p8" }],
+  ["path", { d: "M17 14v.01", key: "11cswd" }],
+  ["path", { d: "M20 11v.01", key: "19e0od" }]
+];
+const ShowerHead = createLucideIcon("shower-head", __iconNode);
+
+export { __iconNode, ShowerHead as default };
+//# sourceMappingURL=shower-head.mjs.map