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/cannabis.mjs

@@ -0,0 +1,23 @@
+/**
+ * @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 22v-4", key: "1utk9m" }],
+  [
+    "path",
+    {
+      d: "M7 12c-1.5 0-4.5 1.5-5 3 3.5 1.5 6 1 6 1-1.5 1.5-2 3.5-2 5 2.5 0 4.5-1.5 6-3 1.5 1.5 3.5 3 6 3 0-1.5-.5-3.5-2-5 0 0 2.5.5 6-1-.5-1.5-3.5-3-5-3 1.5-1 4-4 4-6-2.5 0-5.5 1.5-7 3 0-2.5-.5-5-2-7-1.5 2-2 4.5-2 7-1.5-1.5-4.5-3-7-3 0 2 2.5 5 4 6",
+      key: "1mezod"
+    }
+  ]
+];
+const Cannabis = createLucideIcon("cannabis", __iconNode);
+
+export { __iconNode, Cannabis as default };
+//# sourceMappingURL=cannabis.mjs.map