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/keyboard-off.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: "M 20 4 A2 2 0 0 1 22 6", key: "1g1fkt" }],
+  ["path", { d: "M 22 6 L 22 16.41", key: "1qjg3w" }],
+  ["path", { d: "M 7 16 L 16 16", key: "n0yqwb" }],
+  ["path", { d: "M 9.69 4 L 20 4", key: "kbpcgx" }],
+  ["path", { d: "M14 8h.01", key: "1primd" }],
+  ["path", { d: "M18 8h.01", key: "emo2bl" }],
+  ["path", { d: "m2 2 20 20", key: "1ooewy" }],
+  ["path", { d: "M20 20H4a2 2 0 0 1-2-2V6a2 2 0 0 1 2-2", key: "s23sx2" }],
+  ["path", { d: "M6 8h.01", key: "x9i8wu" }],
+  ["path", { d: "M8 12h.01", key: "czm47f" }]
+];
+const KeyboardOff = createLucideIcon("keyboard-off", __iconNode);
+
+export { __iconNode, KeyboardOff as default };
+//# sourceMappingURL=keyboard-off.mjs.map