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/plugin-transform-dynamic-import/lib/index.js

@@ -0,0 +1,40 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+var _helperPluginUtils = require("@babel/helper-plugin-utils");
+const SUPPORTED_MODULES = new Set(["commonjs", "amd", "systemjs"]);
+const MODULES_NOT_FOUND = `\
+@babel/plugin-transform-dynamic-import depends on a modules
+transform plugin. Supported plugins are:
+ - @babel/plugin-transform-modules-commonjs ^7.4.0
+ - @babel/plugin-transform-modules-amd ^7.4.0
+ - @babel/plugin-transform-modules-systemjs ^7.4.0
+
+If you are using Webpack or Rollup and thus don't want
+Babel to transpile your imports and exports, you can use
+the @babel/plugin-syntax-dynamic-import plugin and let your
+bundler handle dynamic imports.
+`;
+var _default = exports.default = (0, _helperPluginUtils.declare)(api => {
+  api.assertVersion(7);
+  return {
+    name: "transform-dynamic-import",
+    manipulateOptions: (_, parser) => parser.plugins.push("dynamicImport"),
+    pre() {
+      this.file.set("@babel/plugin-proposal-dynamic-import", "7.29.7");
+    },
+    visitor: {
+      Program() {
+        const modules = this.file.get("@babel/plugin-transform-modules-*");
+        if (!SUPPORTED_MODULES.has(modules)) {
+          throw new Error(MODULES_NOT_FOUND);
+        }
+      }
+    }
+  };
+});
+
+//# sourceMappingURL=index.js.map