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-syntax-import-attributes/lib/index.js

@@ -0,0 +1,39 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+var _helperPluginUtils = require("@babel/helper-plugin-utils");
+var _default = exports.default = (0, _helperPluginUtils.declare)((api, {
+  deprecatedAssertSyntax
+}) => {
+  api.assertVersion("^7.22.0 || ^8.0.0-0");
+  if (deprecatedAssertSyntax != null && typeof deprecatedAssertSyntax !== "boolean") {
+    throw new Error("'deprecatedAssertSyntax' must be a boolean, if specified.");
+  }
+  return {
+    name: "syntax-import-attributes",
+    manipulateOptions({
+      parserOpts,
+      generatorOpts
+    }) {
+      var _generatorOpts$import;
+      (_generatorOpts$import = generatorOpts.importAttributesKeyword) != null ? _generatorOpts$import : generatorOpts.importAttributesKeyword = "with";
+      const importAssertionsPluginIndex = parserOpts.plugins.indexOf("importAssertions");
+      if (importAssertionsPluginIndex !== -1) {
+        parserOpts.plugins.splice(importAssertionsPluginIndex, 1);
+        deprecatedAssertSyntax = true;
+      }
+      if (deprecatedAssertSyntax) {
+        parserOpts.plugins.push("deprecatedImportAssert", ["importAttributes", {
+          deprecatedAssertSyntax: true
+        }]);
+      } else {
+        parserOpts.plugins.push("importAttributes");
+      }
+    }
+  };
+});
+
+//# sourceMappingURL=index.js.map