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/pilcrow-right.mjs

@@ -0,0 +1,20 @@
+/**
+ * @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: "M10 3v11", key: "o3l5kj" }],
+  ["path", { d: "M10 9H7a1 1 0 0 1 0-6h8", key: "1wb1nc" }],
+  ["path", { d: "M14 3v11", key: "mlfb7b" }],
+  ["path", { d: "m18 14 4 4H2", key: "4r8io1" }],
+  ["path", { d: "m22 18-4 4", key: "1hjjrd" }]
+];
+const PilcrowRight = createLucideIcon("pilcrow-right", __iconNode);
+
+export { __iconNode, PilcrowRight as default };
+//# sourceMappingURL=pilcrow-right.mjs.map