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/angry.mjs

@@ -0,0 +1,21 @@
+/**
+ * @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: "12", r: "10", key: "1mglay" }],
+  ["path", { d: "M16 16s-1.5-2-4-2-4 2-4 2", key: "epbg0q" }],
+  ["path", { d: "M7.5 8 10 9", key: "olxxln" }],
+  ["path", { d: "m14 9 2.5-1", key: "1j6cij" }],
+  ["path", { d: "M9 10h.01", key: "qbtxuw" }],
+  ["path", { d: "M15 10h.01", key: "1qmjsl" }]
+];
+const Angry = createLucideIcon("angry", __iconNode);
+
+export { __iconNode, Angry as default };
+//# sourceMappingURL=angry.mjs.map