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/cooking-pot.mjs

@@ -0,0 +1,25 @@
+/**
+ * @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: "M2 12h20", key: "9i4pu4" }],
+  ["path", { d: "M20 12v8a2 2 0 0 1-2 2H6a2 2 0 0 1-2-2v-8", key: "u0tga0" }],
+  ["path", { d: "m4 8 16-4", key: "16g0ng" }],
+  [
+    "path",
+    {
+      d: "m8.86 6.78-.45-1.81a2 2 0 0 1 1.45-2.43l1.94-.48a2 2 0 0 1 2.43 1.46l.45 1.8",
+      key: "12cejc"
+    }
+  ]
+];
+const CookingPot = createLucideIcon("cooking-pot", __iconNode);
+
+export { __iconNode, CookingPot as default };
+//# sourceMappingURL=cooking-pot.mjs.map