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/@babel/preset-modules/lib/index.js

@@ -0,0 +1,27 @@
+"use strict";
+
+exports.__esModule = true;
+exports.default = void 0;
+
+var _path = _interopRequireDefault(require("path"));
+
+var _helperPluginUtils = require("@babel/helper-plugin-utils");
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+/**
+ * @babel/preset-modules produces clean, minimal output for ES Modules-supporting browsers.
+ * @param {Object} [options]
+ * @param {boolean} [options.loose=false] Loose mode skips seldom-needed transforms that increase output size.
+ */
+var _default = (0, _helperPluginUtils.declare)((api, opts) => {
+  api.assertVersion(7);
+  const loose = opts.loose === true;
+  return {
+    plugins: [_path.default.resolve(__dirname, "./plugins/transform-edge-default-parameters"), _path.default.resolve(__dirname, "./plugins/transform-tagged-template-caching"), _path.default.resolve(__dirname, "./plugins/transform-jsx-spread"), _path.default.resolve(__dirname, "./plugins/transform-safari-for-shadowing"), _path.default.resolve(__dirname, "./plugins/transform-safari-block-shadowing"), _path.default.resolve(__dirname, "./plugins/transform-async-arrows-in-class"), !loose && _path.default.resolve(__dirname, "./plugins/transform-edge-function-name"), // Proposals
+    require.resolve("@babel/plugin-proposal-unicode-property-regex"), require.resolve("@babel/plugin-transform-dotall-regex")].filter(Boolean)
+  };
+});
+
+exports.default = _default;
+module.exports = exports.default;