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/palette.mjs

@@ -0,0 +1,26 @@
+/**
+ * @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 22a1 1 0 0 1 0-20 10 9 0 0 1 10 9 5 5 0 0 1-5 5h-2.25a1.75 1.75 0 0 0-1.4 2.8l.3.4a1.75 1.75 0 0 1-1.4 2.8z",
+      key: "e79jfc"
+    }
+  ],
+  ["circle", { cx: "13.5", cy: "6.5", r: ".5", fill: "currentColor", key: "1okk4w" }],
+  ["circle", { cx: "17.5", cy: "10.5", r: ".5", fill: "currentColor", key: "f64h9f" }],
+  ["circle", { cx: "6.5", cy: "12.5", r: ".5", fill: "currentColor", key: "qy21gx" }],
+  ["circle", { cx: "8.5", cy: "7.5", r: ".5", fill: "currentColor", key: "fotxhn" }]
+];
+const Palette = createLucideIcon("palette", __iconNode);
+
+export { __iconNode, Palette as default };
+//# sourceMappingURL=palette.mjs.map