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/file-digit.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: "M4 12V4a2 2 0 0 1 2-2h8a2.4 2.4 0 0 1 1.706.706l3.588 3.588A2.4 2.4 0 0 1 20 8v12a2 2 0 0 1-2 2",
+      key: "jrl274"
+    }
+  ],
+  ["path", { d: "M14 2v5a1 1 0 0 0 1 1h5", key: "wfsgrz" }],
+  ["path", { d: "M10 16h2v6", key: "1bxocy" }],
+  ["path", { d: "M10 22h4", key: "ceow96" }],
+  ["rect", { x: "2", y: "16", width: "4", height: "6", rx: "2", key: "r45zd0" }]
+];
+const FileDigit = createLucideIcon("file-digit", __iconNode);
+
+export { __iconNode, FileDigit as default };
+//# sourceMappingURL=file-digit.mjs.map