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/has-proto/README.md

@@ -0,0 +1,57 @@
+# has-proto <sup>[![Version Badge][npm-version-svg]][package-url]</sup>
+
+[![github actions][actions-image]][actions-url]
+[![coverage][codecov-image]][codecov-url]
+[![License][license-image]][license-url]
+[![Downloads][downloads-image]][downloads-url]
+
+[![npm badge][npm-badge-png]][package-url]
+
+Does this environment have the ability to set the [[Prototype]] of an object on creation with `__proto__`?
+
+## Example
+
+```js
+var hasProto = require('has-proto');
+var assert = require('assert');
+
+assert.equal(typeof hasProto(), 'boolean');
+
+var hasProtoAccessor = require('has-proto/accessor')();
+if (hasProtoAccessor) {
+	assert.equal([].__proto__, Array.prototype);
+} else {
+	assert(!('__proto__' in Object.prototype));
+}
+
+var hasProtoMutator = require('has-proto/mutator');
+var obj = {};
+assert('toString' in obj);
+
+obj.__proto__ = null;
+if (hasProtoMutator) {
+	assert(!('toString' in obj));
+} else {
+	assert('toString' in obj);
+	assert.equal(obj.__proto__, null);
+}
+```
+
+## Tests
+Simply clone the repo, `npm install`, and run `npm test`
+
+[package-url]: https://npmjs.org/package/has-proto
+[npm-version-svg]: https://versionbadg.es/inspect-js/has-proto.svg
+[deps-svg]: https://david-dm.org/inspect-js/has-proto.svg
+[deps-url]: https://david-dm.org/inspect-js/has-proto
+[dev-deps-svg]: https://david-dm.org/inspect-js/has-proto/dev-status.svg
+[dev-deps-url]: https://david-dm.org/inspect-js/has-proto#info=devDependencies
+[npm-badge-png]: https://nodei.co/npm/has-proto.png?downloads=true&stars=true
+[license-image]: https://img.shields.io/npm/l/has-proto.svg
+[license-url]: LICENSE
+[downloads-image]: https://img.shields.io/npm/dm/has-proto.svg
+[downloads-url]: https://npm-stat.com/charts.html?package=has-proto
+[codecov-image]: https://codecov.io/gh/inspect-js/has-proto/branch/main/graphs/badge.svg
+[codecov-url]: https://app.codecov.io/gh/inspect-js/has-proto/
+[actions-image]: https://img.shields.io/endpoint?url=https://github-actions-badge-u3jn4tfpocch.runkit.sh/inspect-js/has-proto
+[actions-url]: https://github.com/inspect-js/has-proto/actions