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/building.mjs

@@ -0,0 +1,26 @@
+/**
+ * @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: "M12 10h.01", key: "1nrarc" }],
+  ["path", { d: "M12 14h.01", key: "1etili" }],
+  ["path", { d: "M12 6h.01", key: "1vi96p" }],
+  ["path", { d: "M16 10h.01", key: "1m94wz" }],
+  ["path", { d: "M16 14h.01", key: "1gbofw" }],
+  ["path", { d: "M16 6h.01", key: "1x0f13" }],
+  ["path", { d: "M8 10h.01", key: "19clt8" }],
+  ["path", { d: "M8 14h.01", key: "6423bh" }],
+  ["path", { d: "M8 6h.01", key: "1dz90k" }],
+  ["path", { d: "M9 22v-3a1 1 0 0 1 1-1h4a1 1 0 0 1 1 1v3", key: "cabbwy" }],
+  ["rect", { x: "4", y: "2", width: "16", height: "20", rx: "2", key: "1uxh74" }]
+];
+const Building = createLucideIcon("building", __iconNode);
+
+export { __iconNode, Building as default };
+//# sourceMappingURL=building.mjs.map