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/mouse-pointer-2-off.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: "m15.55 8.45 5.138 2.087a.5.5 0 0 1-.063.947l-6.124 1.58a2 2 0 0 0-1.438 1.435l-1.579 6.126a.5.5 0 0 1-.947.063L8.45 15.551",
+      key: "1qoshx"
+    }
+  ],
+  ["path", { d: "M22 2 2 22", key: "y4kqgn" }],
+  ["path", { d: "m6.816 11.528-2.779-6.84a.495.495 0 0 1 .651-.651l6.84 2.779", key: "mymuvk" }]
+];
+const MousePointer2Off = createLucideIcon("mouse-pointer-2-off", __iconNode);
+
+export { __iconNode, MousePointer2Off as default };
+//# sourceMappingURL=mouse-pointer-2-off.mjs.map