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/projector.mjs

@@ -0,0 +1,27 @@
+/**
+ * @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: "M5 7 3 5", key: "1yys58" }],
+  ["path", { d: "M9 6V3", key: "1ptz9u" }],
+  ["path", { d: "m13 7 2-2", key: "1w3vmq" }],
+  ["circle", { cx: "9", cy: "13", r: "3", key: "1mma13" }],
+  [
+    "path",
+    {
+      d: "M11.83 12H20a2 2 0 0 1 2 2v4a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2v-4a2 2 0 0 1 2-2h2.17",
+      key: "2frwzc"
+    }
+  ],
+  ["path", { d: "M16 16h2", key: "dnq2od" }]
+];
+const Projector = createLucideIcon("projector", __iconNode);
+
+export { __iconNode, Projector as default };
+//# sourceMappingURL=projector.mjs.map