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/server-off.mjs

@@ -0,0 +1,21 @@
+/**
+ * @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: "M7 2h13a2 2 0 0 1 2 2v4a2 2 0 0 1-2 2h-5", key: "bt2siv" }],
+  ["path", { d: "M10 10 2.5 2.5C2 2 2 2.5 2 5v3a2 2 0 0 0 2 2h6z", key: "1hjrv1" }],
+  ["path", { d: "M22 17v-1a2 2 0 0 0-2-2h-1", key: "1iynyr" }],
+  ["path", { d: "M4 14a2 2 0 0 0-2 2v4a2 2 0 0 0 2 2h16.5l1-.5.5.5-8-8H4z", key: "161ggg" }],
+  ["path", { d: "M6 18h.01", key: "uhywen" }],
+  ["path", { d: "m2 2 20 20", key: "1ooewy" }]
+];
+const ServerOff = createLucideIcon("server-off", __iconNode);
+
+export { __iconNode, ServerOff as default };
+//# sourceMappingURL=server-off.mjs.map