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/screen-share.mjs

@@ -0,0 +1,20 @@
+/**
+ * @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: "M13 3H4a2 2 0 0 0-2 2v10a2 2 0 0 0 2 2h16a2 2 0 0 0 2-2v-3", key: "i8wdob" }],
+  ["path", { d: "M8 21h8", key: "1ev6f3" }],
+  ["path", { d: "M12 17v4", key: "1riwvh" }],
+  ["path", { d: "m17 8 5-5", key: "fqif7o" }],
+  ["path", { d: "M17 3h5v5", key: "1o3tu8" }]
+];
+const ScreenShare = createLucideIcon("screen-share", __iconNode);
+
+export { __iconNode, ScreenShare as default };
+//# sourceMappingURL=screen-share.mjs.map