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/grip.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 = [
+  ["circle", { cx: "12", cy: "5", r: "1", key: "gxeob9" }],
+  ["circle", { cx: "19", cy: "5", r: "1", key: "w8mnmm" }],
+  ["circle", { cx: "5", cy: "5", r: "1", key: "lttvr7" }],
+  ["circle", { cx: "12", cy: "12", r: "1", key: "41hilf" }],
+  ["circle", { cx: "19", cy: "12", r: "1", key: "1wjl8i" }],
+  ["circle", { cx: "5", cy: "12", r: "1", key: "1pcz8c" }],
+  ["circle", { cx: "12", cy: "19", r: "1", key: "lyex9k" }],
+  ["circle", { cx: "19", cy: "19", r: "1", key: "shf9b7" }],
+  ["circle", { cx: "5", cy: "19", r: "1", key: "bfqh0e" }]
+];
+const Grip = createLucideIcon("grip", __iconNode);
+
+export { __iconNode, Grip as default };
+//# sourceMappingURL=grip.mjs.map