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/microchip.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: "M10 12h4", key: "a56b0p" }],
+  ["path", { d: "M10 17h4", key: "pvmtpo" }],
+  ["path", { d: "M10 7h4", key: "1vgcok" }],
+  ["path", { d: "M18 12h2", key: "quuxs7" }],
+  ["path", { d: "M18 18h2", key: "4scel" }],
+  ["path", { d: "M18 6h2", key: "1ptzki" }],
+  ["path", { d: "M4 12h2", key: "1ltxp0" }],
+  ["path", { d: "M4 18h2", key: "1xrofg" }],
+  ["path", { d: "M4 6h2", key: "1cx33n" }],
+  ["rect", { x: "6", y: "2", width: "12", height: "20", rx: "2", key: "749fme" }]
+];
+const Microchip = createLucideIcon("microchip", __iconNode);
+
+export { __iconNode, Microchip as default };
+//# sourceMappingURL=microchip.mjs.map